JPH03501979A - Apparatus and method for chromizing objects - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] a Apparatus and method for chromizing objects Background of the invention The invention relates to the coating of objects, in particular as a means of protection, in particular as a means of protection against corrosion. One or more tables. Apparatus and method for applying chromizing coating to surfaces related.

As far as steel is concerned, in terms of its ability to resist various forms of corrosion, It has previously been established in the prior art that the most important alloying element is probably chromium. was known. In addition, steel has resistance to such corrosion and or oxidation. One means of providing the necessary ROM aspect to the The term romizing refers to a process that has been commonly used up until now. has long been known.

As used in the prior art, the term chromizing refers to the treatment of steel. This has come to mean a high-temperature diffusion treatment that alloys the surface with chromium.

Briefly, according to this process, a steel object is placed in a chromium-containing powder in a retort. After embedding, the retort with its contents is heated to high temperature in an oven for several hours.

This heating gasifies the chromium in the powder and deposits it on the steel object, which of steel over a depth with a concentration that depends on a number of metallurgical and processing variables. Diffusion into the matrix of the body. According to the above-mentioned process, the iron-chromium alloy that is the coating becomes steel. This results in a steel object that is metallurgically bonded to the base material of the object. be. Since chromizing is a diffusion process, the structural The modification occurs within the surface of the base material and not on the surface itself. of this thing The importance lies in the fact that diffused chromium physically and metallurgically penetrates the base material surface of steel objects. The diffused chromium replaces some of the iron atoms in the base metal, so the diffused chromium is mixed with the base metal of the steel object. exposed to cracking or peeling characteristic of mechanically bonded coatings in one piece; This means that there will be no chance of it being lost.

It is desirable to use parts that are chromized or have a chrome coating. As is known, there are many fields of application. As a non-limiting example of this Many types of general and/or localized gas-side corrosion and steam-side oxidation There is a need to combat solid particle vaporosphere erosion caused by solid particle scale exfoliation. Mention may be made in particular of the various boiler-related fields in which it is known to occur.

For example, a chemical recovery boiler is an example of such a boiler-related field. medicine The product recovery boiler is a device that recovers and processes chemicals used in bulk factories. medicine A special problem with recovery boilers arises during so-called black liquor or pulp production. Regarding cooling waste liquid. This black liquor is burned as fuel in the chemical recovery boiler. . For many years black liquor was burned in chemical recovery boilers as a means of chemical recovery; Therefore, steam was generated. Chemicals recovered by using a chemical recovery boiler The value of the chemical recovery boiler is typically more than three times the value of the steam generated in this chemical recovery boiler. cloud Needless to say, the steam generated in chemical recovery boilers is a substantial amount, i.e. This reaches half the amount of steam required at the pulp factory. Unfortunately, however, drugs The black liquor burned as fuel in the product recovery boiler is used against the carbon steel ice wall of the chemical recovery boiler. This creates a highly corrosive environment. As a result, it resists this corrosion Until now, boiler tubes used in ice wall panels at chemical recovery facilities have often been used for this purpose. had to be replaced and/or metallized. Therefore In any case, the operation of the chemical recovery boiler must be stopped so that access can be made to it. It is necessary to. Another option is carbon steel with 304 steel. Special composite pipes with an outer cladding of stainless steel may be used; Composite tubes such as are relatively expensive. As an alternative, Chromaji It is recommended to use boiler tubes with chromium coating. Ru.

Particularly when using chromized parts, i.e. parts with chrome coatings. Other examples of boiler-related fields that may be suitable include the field of resource recovery boilers. can be given. The number of landfill sites that can accept municipal waste is increasing. More and more communities are resorting to incinerating municipal waste as it becomes less and less available. It is becoming more and more common. Municipal waste incineration adopted by such communities The means to carry out this process is often a type of boiler called a resource recovery boiler in general industry. It uses the la. However, unfortunately, the composition of municipal waste This is due to the properties of various antibiotics that are thought to be contained in municipal waste. Burning municipal waste in resource recovery boilers often requires at least some of the boiler pipes to be burned. creating conditions that expose the material to corrosion. cities on the scale currently being attempted. Burning waste in a boiler is one of the fields in which boilers have historically been used. As this is a relatively recent field of development, boiler pipes for resource recovery boilers are used to incinerate municipal waste. about the nature of corrosion exposed as a result of There is much to learn about the extent to which pipes are exposed to corrosion. . Despite this, boiler piping that has been chromized in the source recovery boiler, i.e. By using chrome-coated boiler piping, sufficient resistance to corrosion can be achieved. There is sufficient information to suggest that this may be possible.

Boiler related parts using chromized parts, i.e. parts with chrome coating Another example of this field is gasifier components designed for use in coal gasification processes. can be given. The U.S. has developed and put into practical use a coal gasification process that produces synthetic gas from coal. It received considerable attention, especially in the 1970s. Development of such technology During this period, not only the U.S. government but also many large U.S. companies poured in funds to support the It was out. Interest in the United States to carry out coal gasification on a commercial scale The degree of this decline markedly declined with the subsequent decline in oil prices. On the other hand, commercial scale There is currently relatively little interest in realizing coal gasification in the United States. Although not yet, there has been a fair amount of interest in it relatively recently overseas. This conclusion As a result, corrosion that occurs in the internal parts of gasifiers during operation is particularly important overseas. The focus has been narrowed on ways to fight food. As in the case of the resource recovery boiler mentioned above, The nature of corrosion to which the internal parts of the gasifier are exposed during gasifier operation and the There is much to learn about the extent to which internal components are exposed to this corrosion. There are only a few left. Despite this, chromizing the internal parts of the gasifier This type of corrosion can be prevented by treatment, i.e. by applying a chrome coating. There is sufficient information to conclude that successful resistance is possible. It exists.

Coal-fired general boilers have chromized parts, i.e. chrome coatings. This is another example of a boiler-related area where the component may be particularly suitable for use. be. Coal-fired general-purpose boilers, especially supercritical pressure type boilers, are completely covered by ice walls. Subject to physical and/or local erosion. Additionally, this highly aggressive sulfidation It turns out that metallization is not an effective enough tool to combat the environment. On the other hand, Ku Components with ROM coatings may be located in areas where significant metal loss has previously been observed. It was found to be resistant to such sulfide attack and metal loss.

Moving on to the boiler, its superheater section and reheater section are It was known to suffer from corrosion and oxidation from hot ash. A button like this This hot ash corrosion in the superheater section and reheater section of Ira and oxidation becomes the material from ferritic steel to austenitic stainless steel This can be addressed by upgrading. However, ferritic steel and austenite Due to the difference in coefficient of thermal expansion with night stainless steel, ferritic steel is used in boilers. Materials of some or all of the parts of the superheater section and/or reheater section It may be desirable or even necessary to continue to use it as a It is. In such cases, the use of chromizing, i.e. Applying a chromium coating to ash alloy parts is effective in providing resistance to ash corrosion. This allows the base material of these parts, i.e. the frame from which these parts are made, to This will significantly increase the oxidation limit of the errite alloy material. Different coefficients of thermal expansion To further address the issue with boiler modifications, materials that expand at different rates This is a particularly serious problem. i.e. the original design was inspired by the use of ferrite materials. or vice versa, i.e. the original design is replaced with an austenitic material. is based on the use of and replacing this austenitic material with a ferritic material That may not be possible. In this way, it is made of ferrite alloy material. Therefore, there is a need to adopt parts that are However, like this In order to increase the oxidation limit of this ferritic alloy material, there are some It is necessary to do so. Such results are due to internal and external chromizing, i.e. Using parts made of ferrite alloy material with chromium coating on the inner and outer surfaces. It can be obtained by By doing this, it is possible to Providing parts that are expected to have a significantly longer life than parts made from light alloy materials It will be done.

Further mentioning the oxidation issue, the superheater section of the boiler in contact with the gas Steam-side oxidation products that form in the tubes of the tubes and reheater sections have significantly higher gold It is known that there is a risk of generating high temperatures. In addition, the boiler tube internal table Thick oxides can form on the surfaces and cause boiler tube failure. In contrast to this Generally, the oxide scale that forms on chromium-coated surfaces is extremely thin. It turned out to be.

As a result, the oxide scale is extremely thin and chromized or purified. The metal temperature of boiler tubes made of ferrite alloy material coated with ROM remains constant for a long time. It does not increase significantly even during heavy driving.

Next, it is often referred to as corrosion fatigue, circumferential grooving, elephant hiding, etc. This article describes a type of metal wear problem. towards the fireside, i.e. the flames inside the boiler. The side that is exposed to a high front-to-back temperature difference, for example, the side that is normally exposed to radiant heat. Conventional boiler tubes often crack in the circumferential direction. surroundings like this The cause of directional cracking is not fully understood, but it may be caused by thermal stress. believed to be induced. The mechanism of penetration of the base material, that is, the occurrence of cracking. Crab-kinism is the repeated formation of semi-protected oxidation products on the boiler tube surface. This is said to be the result of Ice wall tubes for coal-fired general-purpose boilers, especially supercritical pressure type The ice wall tubes of this type of boiler are subject to sulfur attack, but at the same time they are also susceptible to corrosion. Fatigue cracking, especially corrosion in areas outside the area undergoing severe metal loss Known to suffer from fatigue clubbing. In addition, we will rebuild coal-fired boilers. Radiant wall tubes in the heater section are also subject to this type of cracking, i.e. thermally induced cracking. corrosion resulting in fatigue cracking. Again, the boiler tubes are treated with chromidine. Treating the surface with a chrome coating prevents the above-mentioned types of corrosion from occurring. Fatigue Crabbing, i.e. the thermally induced corrosion fatigue crabking mentioned above. It was shown to be completely resistant.

In summary, protection against oxidation and sulfidation is known to occur on heat transfer surfaces. areas where it is necessary to provide the material with a chromium coating i.e. chromidine In areas where it is known to be effective to protect the surface of the material by applying By way of non-limiting example, power supply, paper manufacturing, petrochemicals, coal gasification and chemical industries. It is easy to see from the above explanation that the following industries can be mentioned.

Continuing further, as mentioned above, applying chromium coating to the surface of materials has been known for a long time. It is being However, today it is not possible to apply a ROM coating like this on the surface of a material. has disadvantageous characteristics in two respects. One is especially for non-parts. As far as applying chrome coatings to surfaces is concerned, up until now it has only been possible to apply chrome coatings to relatively small parts, such as tartars. It was possible to coat chromium on the external surface of parts of dimensions such as bin blades. It lies in the fact that only.

The reason for this is that when applying chromium coating to the surface of a material, this is done at a specific temperature. due to the fact that there is a need to Therefore, as the size of the part increases, the chrome coating Maintaining the entire surface of the part at this specific temperature for the time necessary to apply the coating. becomes increasingly difficult.

Regardless of whether the chrome coating is applied to the external or internal surface of the material, Another disadvantage of the traditional method of applying chrome coatings is that The coating derives from the characteristic that it contains a large amount of grain boundary carbides. this If necessary, see U.S. Pat. No. 4,208,453 and U.S. Pat. Please refer to the specification of Japanese Patent Application No. 4,290°391. Large amount of grains in chromium coating The reason why the presence of grain boundary carbide is considered to be disadvantageous is that the presence of grain boundary carbide This is because the chromium coating increases the susceptibility to intergranular attack in harsh environments. I found out. Minimize the presence of grain boundary carbides in the chromium coating as much as possible. Efforts have been made to overcome this drawback. Condensation in chrome coating One approach taken to minimize the presence of grain boundary carbides is to co-diffusion of vanadium. Idea of co-diffusion of vanadium in chromium is one of the inventors of the present application, E. C.L.E. U.S. patent application filed on July 1, 1987 with one of the co-inventors: This is the gist of National Patent Application No. 68°922. Another way is to The aim was to use a carbon-stabilized low-alloy base material as the material to which the ROM coating was applied.

In this way, the surface can represent one or more numbers of objects, whether external or internal. Used in applications where surfaces are coated with chrome, especially those exposed to corrosion. There continues to be a need for new and improved equipment and methods for applying chrome coatings to such objects. It has existed since ancient times.

Additionally, it is thicker than the chrome coatings that could be obtained using traditional chrome coating methods. There has long been a need for an apparatus and method that can apply a chromium coating to the surface of an object. I came. Furthermore, the chromium concentration is lower than that which could be obtained using traditional chromium coating methods. There has been a long-standing demand for chromium coating equipment and methods that can provide higher chromium concentrations. It is coming. Furthermore, the size of the object whose surface is to be coated with chrome is The size of objects for which it was possible to apply chromium coating to the surface using the ROM coating method Provides an apparatus and method for applying a chromium coating to the surface of this object when the size is larger than I have a request.

It is therefore an object of the present invention to coat the surface of an object with chromium as a means of protecting the object. An object of the present invention is to provide a new and improved apparatus for applying coatings.

Another object of the invention is to apply a chromium coating to the surface of the object as a means of protecting the object. The purpose of the present invention is to provide a new and improved method for applying the present invention.

Still another object of the invention is that the surface to be coated with chrome is the outer surface of the object and To provide an apparatus and method for applying a chromium coating to the surface of an object, such as an inner surface or an inner surface of an object. be.

Another object of the present invention is that the thickness of the applied chrome coating can be reduced using conventional chrome coating methods. Proposes an apparatus and method for coating chrome that is thicker than that which can be obtained. It is to serve.

Yet another object of the invention is that the dimensions of the object on which the chromium coating is to be applied are The dimensions of objects whose surfaces could be coated with chromium using traditional chromium coating methods Another object of the present invention is to provide a chromium coating apparatus and method that has a significant effect on chromium coating.

Another object of the invention is that it is relatively inexpensive and relatively easy to use; Moreover, it is more resistant to corrosion than the chrome coatings traditionally used for the same purpose. An object of the present invention is to provide a chromium coating device and method capable of obtaining a high chromium coating. .

Summary of the invention One aspect of the invention is to apply a chromium coating to one or more surfaces of an object. chromium coatings on the surfaces of objects intended for application, especially those exposed to corrosion. It is an object of the present invention to provide a new and improved device for applying coatings. This device is preferably molded. Includes a fixed foundation made of refractory material. On this fixed foundation, there are There is a retort supported at intervals by a plurality of support members arranged at intervals. child Inside the retort is placed the object to be coated with chrome. of this retort An inlet opening is suitably formed at the location where the fluid medium is allowed to flow through the inlet opening. Supplied inside the root. Outlet openings are appropriately formed elsewhere in the retort. The fluid medium entering through the aforementioned inlet opening flows through the retort and then exits through this outlet opening. I'm going to go. The device of the invention further moves to a location and leaves this location. A heating means is provided, and when the heating means is in this location, the retort is activated by the heating means. It also includes a furnace designed to heat uniformly at a predetermined temperature for a predetermined time. It is. Similar to a retort, this furnace has an inlet opening at one location; Via this a fluid medium is supplied into the furnace interior. This furnace also has an outlet in a different location. The fluid medium entering through the inlet opening exits through this outlet opening after flowing through the furnace. so that Finally, the device of the present invention can be suitably arranged in a sealed relationship between the furnace and the fixed foundation. This acts to seal the furnace, thereby allowing heating by the heating means provided. It includes a sealed part that is designed to be

Another aspect of the invention is intended for use in applications where objects are particularly exposed to corrosion. A new and improved method for applying a chrome coating to one or more surfaces of objects The purpose is to provide a method. This method preferably involves forming a molded refractory material into a A fixed foundation is provided, and multiple support members are placed at intervals on this fixed foundation. The retort is mounted in a supporting relationship on these support members, and the bottom of the retort is Forms a layer of powder consisting of a mixture of ammonium chloride, alumina and ferrochrome , place a layer of the object to be chromium-coated on top of the powder layer in the retort, and Cover the body layer with a layer of powder and in this way alternately apply the chrome coating to the retort. Add layers of the object to be treated and layers of powder until the retort contains the desired number of objects. , cover this last layer of material with a predetermined thickness of powder, cover the retort, and store it on the spot. This is sealed, a furnace with heating means is placed around this retort, and this furnace is sealed. This seals the retort from the environment surrounding the furnace and prevents the retort from being heated by the furnace's heating means. Provide fluid medium inside and around the retort while starting to heat the retort. the retort at a first predetermined temperature for a predetermined period of time. heat the retort to a second predetermined temperature, and then cool the retort to a second predetermined temperature. Remove the furnace from the storage, remove the lid from the retort, and drain any powder residue and and chromium-coated objects, and remove the remaining chromium-coated objects from these chromium-coated objects. Includes a step of cleaning the powder.

Brief description of the drawing Figure 1 shows the application of a chromium coating to one or more surfaces of an object according to the invention. 1 is a schematic diagram of the device.

FIG. 2 is an enlarged schematic diagram of the retort section of the apparatus of FIG. 1 according to the invention.

FIG. 3 shows the retort portion of the apparatus of FIG. 1 according to the present invention substantially along line 3--3 of FIG. It is a figure shown in a cross section.

Figure 4 shows the application of a chromium coating to one or more surfaces of an object according to the invention. A pair of tubular bodies coated with chrome on both the outer and inner surfaces by means of an apparatus and method. It is a perspective view of a member.

Figure 5 shows the application of a chromium coating to one or more surfaces of an object according to the invention. 1 is a perspective view of a tubular member having a chrome coating applied to its outer surface by the apparatus and method; FIG.

FIG. 6 shows the application of a chromium coating to one or more surfaces of an object according to the present invention. 1 is a perspective view of a non-tubular member having a chromium coating applied to its outer surface by the apparatus and method; FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring in particular to FIG. 1, there is shown an apparatus indicated generally by the numeral 10. Ru. According to one aspect of the invention, the device 10 is exposed to corrosion, particularly Chromium coating on one or more surfaces of the object to be used in the field of application It is designed and operated for the purpose of administering.

First, the nature of the structure of this device 10 will be described. For this purpose, it is necessary to draw 1, see FIGS. 2 and 3. As best understood from Figure 1, the apparatus 10 includes a fixed foundation. This fixed foundation is indicated in its entirety by the reference numeral 12 in Figure 1. It is. According to a preferred embodiment of the invention, the fixed foundation 2 is preferably molded. Made of fireproof material. The fixed foundation 12 is designed to perform two functions. It is. That is, this fixed foundation 12 has the properties of a support base for the device 10. do. Second, since it is formed of molded refractory material, the fixed foundation 12 is similar to the device 10. The apparatus 10 is located between a facility such as a factory floor (not shown) and a heat source. It acts to form an insulating barrier.

1 of the drawings, the fixed foundation 12 has a plurality of support members thereon. are supported with a distance between adjacent ones. Multiple of these for simplicity Each of the supporting members is designated by the same reference numeral 14 in rXJl. Ru. As with the fixed foundation 12, these plurality of support members 14 are preferably Each is made of molded refractory material. Furthermore, similar to the fixed foundation 12, multiple Each support member acts both as a support surface and as a thermal insulation barrier. It is designed as such.

The support surface provided by the plurality of support members is indicated by the reference numeral 16 in FIGS. 1, 2 and 3. It's for Torto.

The retort 16 includes a chrome coating on one or more surfaces. Place the object you are trying to do.

Another method of the present invention is to apply a chromium coating to the surface of an object placed in the retort 16. It becomes two sides. This method will be explained in detail below. However, in Figure 1 To illustrate the nature of the construction of apparatus 10, retort 16 may include one or more Contains objects whose upper surfaces are to be coated with chrome and forms a chrome coating on these objects. The package can be heated to a uniform predetermined temperature over a predetermined period of time. It will suffice to say that it is designed to function as an enclosure. others Therefore, according to the best embodiment of the invention, retort 16 preferably has a large number of relatively large For example, a large number of relatively long tubular pieces of gold heated to temperatures on the order of 2100°F. shall be constructed of any suitable conventional material of sufficient strength to support metallic objects therein. Ru. Furthermore, in order to simplify the structure of the retort 16, the best embodiment of the present invention , preferably a rectangular structure formed by a base indicated by the reference numeral 18. It has a body. The base 18 has four upright side walls indicated at 20. this are connected by any conventional connection means (not shown) to form a closed box type structure. form the body. Additionally, retort 16 includes a lid designated at 22 . This lid 2 2 is the top of the box structure formed by the base 18 and the upright side walls 20 connected thereto. removably attached to the surface and coated with chrome on one or more surfaces. For the purpose of inserting the object to be coated, or for removing a chrome-coated object from inside. For the purpose of taking it out, it is made to be close to the inside of the retort 16.

Referring further to the lid 22, this lid has a surface on one or more surfaces. Once the object to be coated with chrome is placed in the retort, proceed as described below. When heating to form the chrome coating, the base 18 and upright side walls 20 It is designed to seal in-situ the box structure formed by the process.

Concluding the description of the structural nature of the retort 16, the retort 16, as detailed below, It is noted that port 16 is provided with an inlet passageway means in a first position. This entrance street The path means is designated at 24 in FIG. The inlet passage means 24 contains an inert fluid. operatively so as to allow medium to be fed into the interior of the retort 16 via the first It is formed at the appropriate position. In addition, the retort 16 has an outlet port in another position. It has road means. This outlet passage means is indicated schematically at 26 in FIG. exit passage Means 26 provides an inert stream supplied to the interior of retort 16 via inlet passage means 24. This allows the body medium to flow through this retort 16 and then exit from it. It works like this. According to the best embodiment of the invention, the inlet passageway means 24 and the outlet Passage means 26 may be any suitable device capable of performing its desired function as described above. Any suitable conventional type may be used.

Continuing with the explanation of the nature of the structure of the device IO, as can be seen clearly in Figure 1, this The apparatus tIO includes a furnace designated 28. According to the best embodiment of the invention The furnace 28 is preferably substantially square in shape. Explain in more detail The furnace 28 is made to have a shape complementary to the shape of the retort 16. However, its dimensions are larger than those of the retort 16, and the furnace 28 is larger than the retort 16. a first position in which the furnace 28 is covered and a second position (not shown) in which the retort 16 is not covered; It allows you to move between. For the retort 16 of this furnace 28 Appropriate gripping means are provided for movement. This gripping means is shown in Figure 1. It is in the form of a plurality of conventional lugs, as shown at 30. Lug 30 is suitable are spaced apart from each other so as to protrude from the top 32 (FIG. 1) of the furnace 28. It is arranged appropriately. The lugs 30 are removed by an industrial type crane or in this manner. Furnace 28 may be connected to retort 16 by any other similar equipment suitable for use for that purpose. to a position that surrounds it, or to move it out of this position. It is designed to. However, without departing from the spirit of the invention, 0, any conventional gripping means suitable for the purpose mentioned above may be employed. You could also do that.

To further discuss the nature of the structure of the furnace 28, as seen in FIG. has heating means. The heating means are designated by the reference numeral 34 in FIG. . Heating means 34 is, in the best embodiment of the invention, suitably mounted in supporting relationship within furnace 28. It consists of a number of electrical heating elements 36 arranged. Furnace 28 as shown in FIG. When positioned to cover the retort 16, the multiple electric heating elements 36 It acts to uniformly heat the tort 16 to a predetermined temperature for a predetermined time, thereby Chromium coating on one or more surfaces of the retort 16 It heats the object to be heated. where this given temperature and given With regard to time, in the best embodiment of the invention this predetermined temperature is preferably 2100'F and the predetermined time is preferably 10 hours. For this reason, the main According to In order to successfully achieve any desired goal, this object must be coated with chrome. The surface must be uniformly heated to a temperature of 2100'F. This temperature is the whole Whatever the dimensions of the object, i.e. the length, width, and height of the object, must be maintained over time. In this connection, no matter the dimensions of the object The whole area was heated to a temperature of 2100"F evenly and continuously for 10 hours. This has proven to be even more difficult to maintain. Finally, according to the present invention uniformly heats the surface to a temperature of 2100°F, especially on relatively large objects. and then maintain the object continuously for 10 hours at a temperature of approximately 2100'F. Forming the chromium coating by heating means 34 provided in the furnace 28 as appropriate. This can be achieved with a large number of electric heating elements 3'6 as described above.

Gas or oil heating means successfully form the desired chromium coating on the surface of the object. It was found that this method is not suitable as a means for uniform heating.

Describing the nature of the structure of the furnace 28 again, as is clear from FIG. Like the retort 16 previously described, it is provided with inlet passage means. This entrance passageway The stage is designated at 38 in FIG. The inlet passage means 38 is suitably located in the first position of the furnace 28. The fluid medium is supplied to the interior of the furnace 28 from here. moreover , the furnace 28 likewise has outlet passage means at another location. This exit passage means is shown in Figure 1. It is shown with reference numeral 40. The outlet passage means 40 is connected from the inlet passage means 38. A fluid medium supplied to the interior of the furnace 28 exits through the furnace 28 after flowing through the furnace 28. It acts on According to the best embodiment of the invention, the inlet passage means 38 and the outlet passage means 40 both function as desired, i.e., can function as described above. Any suitable conventional structure capable of this can be employed.

Concluding the description of the nature of the construction of furnace 28, in accordance with the best embodiment of the invention, the furnace A plurality of electrical heating elements 36 of heating means 34 supported within 28 are conventional insulating means. (not shown), and the heat generated by these multiple electric heating elements 36. The retort 16 and the retort are arranged so that the generated heat does not escape to the outside of the furnace 28. to achieve the desired heating of the objects in the retort 16 as described above. Ensuring successful formation of chrome coating.

Any conventional insulating means can be used for this purpose as described above.

Finally, as far as the nature of the structure of the device 10 is concerned, as best seen from FIG. The device IO includes sealing means. This sealing means is designated at 42.

As shown in FIG. 1, this sealing means 42 can be interposed between the furnace 28 and the fixed foundation 12. It is designed to be able to For this reason, the sealing means 42 ensures that the retort 16 is As shown, it is disposed on a plurality of support members 14 and supported on a fixed foundation 12. and the furnace 28 is moved to a position surrounding the retort 16 to create the retort shown in FIG. sealing between the furnace 28 and the fixed foundation 12 when in position relative to the furnace 28 and the fixed foundation 12. It is designed to function as intended. That is, the sealing means 42 seals the furnace 28. The retort 16 is then sealed and the object taken from the furnace 28 is placed in the furnace 28 as described below. A plurality of electric heating elements 36 of the heating means 34 are used to heat the device to a desired temperature for a desired time. It is intended to act in such a way as to make it possible to Made like this to withstand the weight applied to the furnace 28 and resist high temperatures for extended periods of time. Any known sealing means that can be used may be used as a sealing means for this device. Let's do it. Furthermore, for convenience of use, the sealing means 42 may be installed in the furnace 28 as appropriate. and moved therewith into sealing engagement with the fixed foundation 12 or sealing therewith. It is preferable to enable it to be disengaged and disengaged.

Next, we turn our attention to another aspect of the invention. As detailed below, the present invention is a method of applying a chromium coating to one or more surfaces of an object, especially a corrosion-resistant one or more objects of a type used in applications where they are exposed to food There is a method of applying chrome coating to the surface of. In order to carry out this method, the best part of the present invention is According to a good embodiment, each of FIGS. 1, 2 and 3 may be illustrated in whole or in part. Preferably, the apparatus 10 shown and described above is used.

Continuing with this aspect of the invention, a representation of one or more numbers of objects The method for applying a chromium coating to a surface consists of the steps described below. These works In order to explain the process, reference is made to the drawings, particularly FIGS. 1, 2 and 3. this The first step in these steps is to first prepare a fixed foundation, for example in the form of the fixed foundation 12 shown in Figure 1. It is to establish a fixed foundation. This fixed foundation is preferred according to the best embodiment of the invention. are made from any suitable conventional molded refractory material. Next, consider the multiple support members. For example, the supporting members 14 shown in FIG. 1 are fixed at appropriate intervals between adjacent ones. Place it on the foundation. Then a retort with a lid, according to the best embodiment of the invention. If the retort 16 shown in FIGS. 1, 2, and 3 is mounted on multiple supports with the lid removed, It is placed in a suitably supported relationship on the support member.

Continuing the description of the steps in the method of the invention, the lid is removed from the retort and the retort is heated. access to the inside of the retort and then spread a layer of powder on the bottom of the retort.

shall consist of a mixture of ammonium chloride, alumina and ferrochrome. Next In this case, layers of objects, e.g., multiple objects, i.e., multiple pairs of joints as shown in FIG. 5 or a plurality of single tubular members as shown in FIG. Multiple objects, such as the multiple non-tubular members shown in Place on top of a layer of the above-mentioned powder. However, each of FIGS. 4, 5, and 6 The objects illustrated here are examples of objects whose surfaces will be coated with chromium by implementing the method of the present invention. It should be understood that this is not too much. i.e. other types of objects, non-limiting examples. 4, 5, and 6. The method of the invention can be used without departing from the spirit of the invention as well as the objects shown in each of can be carried out to apply a chromium coating to the surface. Now, place it inside the retort This layer of parts is made of the same powder as the layer of powder spread at the bottom of this retort. i.e. with a layer of powder consisting of a mixture of ammonium chloride, alumina and ferrochrome. cover.

Following this step, a layer of the object and a layer of powder of the same mixture as described above are placed in the retort. until the volume of the retort is full or the number of objects required is equal to the number of objects that fill the retort. If the number of objects is small, the objects are formed alternately in the retort until the required number of objects is reached. . The top layer, the last object layer, is then made with a powder layer of the same mixture as previously described. cover. According to the best embodiment of the invention, this powder layer is of a predetermined thickness.

Once the last object layer has been covered with a powder layer of a predetermined thickness, the lid or retort Position the lid appropriately over the retort to prevent access to the inside of the retort, then and any conventional sealing means suitable for sealing purposes, such as welding i.e. The lid is sealed by welding it in place on the retort.

In this way, the desired number of objects on which a chromium coating is to be formed are retorted. After filling the retort and capping the retort, the retort is placed in a furnace containing heating means. Position it in a surrounding relationship. The furnace is therefore moved to a position surrounding the retort. It is also designed so that it can be moved away from here. of the present invention According to the best embodiment, the furnace is preferably constructed like furnace 28 illustrated in FIG. Realize it as something. Is the furnace 28 the furnace used when carrying out the method of the present invention? Whether or not the present invention method of heating a relatively large object to a predetermined temperature for a predetermined period of time has been successfully applied. This is important for implementation. According to the present invention, once each object is It is heated completely uniformly to a constant temperature, and then heated to this uniform predetermined temperature for a predetermined period of time. It is maintained continuously for a relatively long period of time, about 10 o'clock. - alternating layers Once placed in the relevant positions surrounding the retort as described above, the furnace or retort This seals the furnace from the surrounding external environment. According to the best embodiment of the invention For example, the sealing of the furnace and retort is preferably provided by sealing means shown at 42 in FIG. This is accomplished using similar sealing means.

After that, the process of heating the object placed in the retort to a predetermined temperature for a predetermined time begins. Melt. Heating of this object is accomplished by means of heating means provided in the furnace for this purpose.

At the same time as starting this object heating, the fluid medium is placed in the retort for this purpose. The interior of the retort is fed through inlet passage means of conventional construction, suitably configured. this The fluid medium is designed to act to expel air from inside the retort. It is. After this fluid medium has flowed inside the retort, it can be exit through exit passage means of conventional construction. This stream fed inside the retort In addition to the body medium, at the same time the inside of the furnace, i.e. around the retort, is provided for this purpose. The further fluid medium is supplied via inlet passage means of conventional construction suitably formed in the furnace. child The fluid medium supplied to the inside of the furnace, i.e. the fluid medium supplied around the retort. performs an air expulsion action, similar to the fluid medium supplied inside the retort. . More specifically, the fluid medium supplied inside the furnace or around the retort is act to expel air from the area supplying this fluid medium. It is. The fluid medium passes through the interior of the channel through an outlet suitably provided in the furnace for this purpose. Exit the furnace through the passageway.

From this point on, the heating of objects inside the retort by the heating means installed in the furnace Continue until the body is uniformly heated to a first predetermined temperature, then these The object is maintained at this first predetermined temperature continuously for a predetermined period of time. this place After a certain period of time, the heating means installed in the furnace are deactivated, and the tolt and The object placed inside the retort is allowed to cool.

This cooling of objects placed in the retort ensures that these objects uniformly reach a second predetermined temperature. Continues until cooled.

Once this second predetermined temperature is reached, the furnace is removed from position surrounding the retort. Next Remove the lid from the retort. When the lid is removed, the remaining powder mixture and surface Remove the chrome-coated object from the retort. Then these objects Clean off any remaining powder from the surface. In this way, remove the remaining powder from the object. Once the dust has been removed, these objects are then heat treated and/or subjected to Add any other manufacturing steps deemed desirable.

By way of non-limiting illustration, an example of the implementation of the method according to the invention will now be described. child The embodiment seeks to form a chromium coating on one or more surfaces. Let the object be a tubular member 44 shown in FIG. Furthermore, this implementation of the method according to the invention For illustrative purposes, the surface of this tubular member 44 to which the chrome coating is to be applied is its outer circumferential surface. The tubular member 44 is provided with a chrome coating indicated by reference numeral 46 in FIG.

A chromium coating, such as the chromium coating indicated by reference numeral 46 in FIG. According to the present invention, the following is preferably applied to the outer peripheral surface of a tubular member such as the shaped member 44. Perform the steps described in . First, a fixed base made of a suitable molded refractory material as shown in Fig. A fixed foundation like foundation 12 is provided. Next, the plurality of support members 14 shown in FIG. A plurality of supporting members, such as place Thereafter, the retort 16, such as the one shown in FIGS. 1, 2 and 3, is preferably A structured retort with a lid is mounted on multiple support members with the lid removed. Place it and support it with a fixed foundation as appropriate.

The lid has been removed from the retort, allowing access to the inside of the retort. , spread a layer of powder evenly over the bottom of the retort to a thickness of approximately 1/2 inch.

The powders used for this purpose are: 3% ammonium chloride, 55% alumina, ferrochloride. It is in the form of a mixture consisting of 42% aluminum. In this regard, the present invention provides 75% of the powder residue left after applying the chrome coating to the body surface is replaced with new powder. It is possible to mix and reuse at a ratio of approximately 25%. Now, as mentioned above After spreading the powder layer, a layer of the first tubular member 44 is placed over the powder layer on the bottom of the retort. Form on top. However, the layers of this first tubular member 44 and similar Before placing the next layer of tubular members 44 into the retort, each layer of tubular members 44 is First, expel the air by passing an inert gas such as argon inside. . Furthermore, each of the tubular members 44 of each layer formed in the retort in this manner Once the air has been removed from the area, a plug of suitable construction, preferably made of sheet metal, The plugs are snugly fitted onto each end of each of the tubular members 44.

Once this first layer of tubular member is formed in the retort, the bottom of the retort Spread a layer of the same powder mixture approximately 1/2 inch thick onto the first tubular member. Form on top of the layer. This is followed by a layer of tubular member 44 and approximately 1/2 Alternating inch-thick layers of powder are formed in the retort until the retort's capacity increases. The limit for accommodating layers of tubular members 44 is reached or the desired number of layers of tubular members are formed. Stop when done. In the embodiment of the invention illustrated in FIGS. 2 and 3, the tubular member 4 The layer 48 of No. 4 has 6 layers, approximately 1/2 inch including the powder layer spread on the bottom of the retort. A layer of powder having a thickness of 1 is indicated by 5o. In the last or exemplary embodiment 6 After forming the second layer of tubular member 44 in the retort, this last layer 48 is Approximately 4 inches of powder of the same mixture as the powder layer 50 described above is placed in the root. 2 to form a powder layer indicated by reference numeral 52 in FIG.

The retort is then capped and sealed by welding. Following this, Leto The inlet passage means and outlet passage means suitably formed in the retort are emptied from the interior of the retort. of a fluid medium, e.g. an inert gas such as argon, suitable for expelling air. Connected in fluid flow relationship to a source suitable for supply. Then, for example Move the furnace over the retort using a conventional industrial crane with a This allows the heating means of the furnace to connect to the tubes placed in the retort as described above. The shaped member 440 allows the layer 48 to be heated. Move the furnace to a position surrounding the retort. After the movement, the inlet passage means and the outlet passage means are filled with an inert material such as argon. Connect to a suitable supply source of a fluid medium, which is a reactive gas, in a fluid flow relationship, and That is, it allows air to be expelled from the area surrounding the retort.

Next, heating of the tubular member 440 layer 48 by the heating means of the furnace is started. This furnace Simultaneously with the start of heating of the layers of the tubular member by thermal means, an inert gas is introduced into the inlet of the retort. from the passage means into the interior of the retort and through the inlet passage means of the furnace; Begin to flow into the surrounding area of the furnace. The layer 48 of the tubular member 44 placed within the retort During the heating stage, fumes are generated. This hume flows inside the retort. The inert gas is transported out of the retort via the outlet passage means and further into the furnace. The inert gas flowing therein is carried out through the outlet passage means of the furnace.

Preferably these exit through the retort outlet passage means and the furnace outlet passage means. fumes and inert gases before being discharged to the atmosphere according to the illustrated embodiment of the invention. so that it flows into the chimney. This chimney is designated 54 in the drawings. Hi Once the yum begins to form, it can be applied using any conventional igniter (not shown). Please light it. The ignition of this Huyum is done by the Huyum who takes out the retort and this. This is done after leaving the enclosing furnace area, which allows Huyum to ensure that this burns before being released into the Tubular member 4 placed in a retort by heating means of a furnace Heating of the layer 48 of 4 and the furnace area disposed surrounding the retort and the retort. In this case, for example, if the chrome coating to be applied is This continues until the outer circumferential surface of the shaped member 44 is formed. The coldest point in the retort However, the first predetermined temperature of 2100°F is reached.

Further, this predetermined temperature of 2100'F is then maintained for the desired 10 hours. be done. In this regard, the chrome coating to be applied is applied to the outer peripheral surface of the tubular member 44. If the surface of such other object is not chromium coated, the surface of such other object may be successfully coated with chrome. The predetermined temperature to be heated to provide the For example, temperatures below 2100'F and in the range of 1700°F to 2100°F. Maybe. Similarly, in cases other than coating the outer peripheral surface of the tubular member 44 with chrome, should be continuously maintained at the predetermined temperature for a period other than 10 hours, for example 10 hours. It may take more than an hour.

Tubular member 44 is heated to a predetermined temperature, i.e., 2100°F, and maintained at that temperature for a predetermined time. That is, after 10 hours of continuous heating, the heating means of the furnace is turned off and the retort and Stop the flow of inert gas through the area of the furnace surrounding the retort and the retort. Cooling of the layer 48 of the tubular member 44 placed in the container is started. tube placed inside the retort This cooling of layer 48 of shaped member 44 causes the hottest portion within the retort to reach a second predetermined temperature. Continue until cooled to . of the layer 48 of the tubular member 44 placed within the retort. In this case, this second predetermined temperature is 400°F. The chrome coating to be applied If it is not a chrome coating applied to the outer circumferential surface of the tubular member 44, the This second predetermined temperature for successfully applying a chromium coating to the surface is other than 400@F. It can be temperature. The hottest point in the retort reaches the second predetermined temperature of 400'F. Once the furnace has cooled, the inlet passage means and outlet passage means of the furnace are removed as appropriate and the furnace is reassembled. Make it possible to remove it from the position surrounding the tort. Then this furnace was equipped with a rug. The retort is moved from its surrounding position by a conventional industrial crane. . When the furnace is moved from the retort in this way, the inlet passage means and the outlet passage means are also It will be removed like that. Finally, remove the lid from its seal with the retort.

After removing the lid from the retort, any powder remaining in the retort and Remove the layer 48 of the tubular member 44 that was placed in the. Then each tubular member 44 Clean to remove any powder adhering to it. Also, if necessary, tubular members 44 is heat treated. After heat treating the tubular member 44, its physical integrity is inspected. If necessary, the tubular member 44 is straightened and the outer peripheral surface is coated with chrome. It corrects any deformations that may have occurred during the process. Thereafter, the tubular member 44 is Make any required welded connections and any additional weld connections that need to be made to this tubular member. Any other related processing may be performed.

Following this, the tubular member 44 is again subjected to the necessary heat treatment. Or is it? Then, the final step of applying chromium coating to the outer circumferential surface of each of the tubular members 44, that is, A final inspection of each tubular member 44 is performed.

The method of the present invention has been described above with respect to a tubular member 44 whose outer peripheral surface is coated with chromium coating 46. Although described in detail, it goes without saying that the method of the present invention does not fulfill the spirit of the present invention as described above. Applying a chrome coating to one or more surfaces of other objects without deviation. It can also be applied to For this reason, the method of the invention can be used, for example, without limitation. For example, an object such as a connected tubular member as shown at 58.59 in FIG. Equally useful for applications where the purpose is to apply a chrome coating to one or more surfaces. can be done. In FIG. 4, the inner peripheral surfaces and Examples include chromium coatings shown at 60 and 62 on the outer peripheral surface. Also in Figure 6 A chrome coating indicated by 66 is formed on the entire outer surface of the non-tubular member indicated by 54. An example is shown.

Next, as described above, we will discuss modifications that allow the method of the present invention to be carried out without departing from the spirit of the present invention. I will talk about this. According to this, additional strength is added to one or more surfaces. In order to apply the chrome coating, the chrome coated surface is shot In other words, it is done. The effect of shot peening in the manufacturing process is well known to those skilled in the art. This is a well-known fact. Prior to the present invention, chrome coatings applied in accordance with the present invention The coated surface can be shot peened without adversely affecting the effectiveness of the coating. It was completely unknown that it was possible.

However, chromium coating is the result of the chromium component being applied to the surface of the object in a slurry state. The chromium component is applied as a powder together with ammonium chloride and alumina. Formed as a result of practicing the invention, whether mixed as a powder or applied as a layer The coated chrome coating is then shot peened, which gives the surface a shot peened finish. All the benefits known to be obtained by chroming The ability of the chrome coating to resist corrosion without adversely affecting the effectiveness of the coating, i.e. This can be achieved without sacrificing power.

Therefore, to summarize very briefly, the chromizing process consists of one or more A steel object to be coated with chrome on a number of surfaces in a retort the retort, the retort is sealed, and then the retort is sealed. The tort and its contents are heated to a predetermined high temperature in a furnace for a predetermined period of time, such as several hours. It consists of heating for a period of time. As a result of this heating, the chromium content in the powder mixture becomes gas and deposits on the surface of steel objects embedded in the powder mixture in the retort. of chromium into the metal, i.e. into the surface of the steel object, depending on various metallurgical variables and processes. It diffuses to a depth and concentration that depends on process variables. As a result, the steel object An iron-chromium alloy coating is formed on the surface, which becomes an integral part of the base material and is metallurgically bonded. It matches. Because it is a diffusion process, the structural transformation occurs within the surface rather than on the surface. It occurs in

It was previously reported that grain boundary carbides are characteristically present in chromized structures. It was known from In addition, under harsh environments, such grain boundary carbide It is also known to increase the susceptibility of chromium coatings to intergranular attack. Therefore, there are few At least in such a harsh environment, the grain boundary carbides present in the chromium coating are It is desirable to minimize the amount of According to the present invention, one or more objects can be results from the implementation of this method in the application of chromium coatings to a larger number of surfaces. The presence of grain boundary carbides within the dichromium coating is effectively reduced, resulting in Intergranular corrosion, which is known to make chromium coatings more sensitive to corrosion, A chromizing coating is obtained that is characterized by maximum resistance to corrosion. It is.

Thus, according to the invention, one or more surfaces of an object are provided with a protective layer. A new and improved apparatus for applying chrome coatings is provided. Furthermore, according to the present invention If so, one or more surfaces of the object may be coated with chrome for protection. A new and improved method is provided. Furthermore, according to the present invention, one of the objects or more surfaces are coated with chrome, and this chrome coating is Apparatus and methods are provided for application to surfaces and/or interior surfaces. moreover Furthermore, the apparatus and method of the present invention for applying a chromium coating to the surface of an object are be applied to a thickness greater than that which can be obtained by using conventional chrome coating methods; It is characterized by Furthermore, according to the present invention, what can be achieved using conventional chromium coating methods is Chromium coating on the surface of an object with a chromium concentration higher than that which can be achieved by Apparatus and methods are provided. In addition, this invention applies a chrome coating to the surface of objects. The chromium coating apparatus and method are suitable for use when an object whose surface is to be coated with chrome is coated with conventional chrome. be larger than the dimensions of the object whose surface can be coated with chrome using the covering method; It is characterized by Further, the present invention provides a relatively inexpensive, relatively easy to apply and form The chrome coating is more resistant to corrosion than conventional chrome coatings used for the same purpose. An apparatus and method for applying a highly resistant chromium coating to the surface of an object is provided.

Although preferred embodiments of the present invention have been described above, the present invention extends to these specific embodiments. The present invention is not limited to, and may be modified and modified without departing from the spirit of the present invention. Of course, it is inclusive.

This type of cracking, i.e., thermally induced cracking, may also occur in pipes. Publication (Article 184-8 of the Patent Act) December 25, 1990 1. Display of patent application PCT/US89102121 , name of invention Apparatus and method for chromizing objects 3, Patent Applicant Address: Prospect, Windsor, 06095, Connecticut, USA Hill Road 1000, Name Compassion Engineering Parakeet - Horated 4, Agent 519 Hibiya Park Building, 8-1 Yurakucho-chome, Chiyoda-ku, Tokyo 100 (Telephone 213-0686) 5. Date of submission of written amendment: July 2, 1990 6. Attachment Catalog of supporting documents Mother-in-law MF; - The method of handling a dirty table, a rotary table, etc. is due to corrosion fatigue. Causes racking. In this case too, the boiler tubes should be chromized. , i.e. applying a chromium coating to its surface is a method of the type described above. like this The method shown in FIG. 2 of U.S. Pat. No. 2,836,513 The work piece 20 is placed in a container 26 whose bottom and sides are closed and whose top is open. To illustrate the nature of the structure of the retort 10, the retort 16 can be to accommodate objects whose surfaces are to be coated with chrome and to form a chrome coating on these objects. enclosure that allows heating to a uniform predetermined temperature over a predetermined time It will suffice to say that it is designed to function as a body. For this reason , according to the best embodiment of the invention, the retort 16 preferably has a plurality of relatively large Objects such as large numbers of comparative objects heated to temperatures on the order of 2100°F (1135°C) formed of any suitable conventional material of sufficient strength to support a long tubular metal object therein It shall be. Furthermore, in order to simplify the structure of the retort 16, the present invention In the best embodiment, it is formed by a base, preferably designated 18. It has a rectangular structure. This base 18 has four upright side walls designated 20. have These are connected and sealed by any conventional connection means (not shown). Form a box-shaped structure. Additionally, the retort 16 includes a lid designated by the numeral 22. Ru. The lid 22 is formed by a base 18 and an upright side wall 20 connected thereto. Removably attached to the top of the box structure with one or more chrome coatings For the purpose of enclosing the object to be coated on the surface of In order to take out the body inside, it is made to be close to the inside of the retort 16. lid Further referring to 22, this lid can be attached to one or more surfaces. Items to be coated with ROM, to apply a chromium coating to the contents, i.e., one or more surfaces of It heats the object. Now for this given temperature and given time. Additionally, in the best embodiment of the invention, this predetermined temperature is preferably 2100°. F (1135°C) and the predetermined time is preferably 10 hours. For this reason, books According to the invention, the quality and thickness of the chromium coating on one or more surfaces of the object In order to successfully achieve the desired results, this object must be coated with chrome. must be uniformly heated to a temperature of 2100'F (1135°C) . This temperature is independent of the overall dimensions, i.e. length, width, and height of the object. It must be maintained uniformly for 10 hours. In this connection, objects The larger the size of the Moreover, maintaining it continuously for 10 hours may be even more difficult. Understood. Finally, according to the invention, 2100 The surface is heated uniformly to a temperature of 2100'F (1135°C), and then heated to approximately 2100'F (1135°C). 135°C) for 10 hours. The formation of the heating means 34, which is suitably provided in the furnace 28, can be carried out by using the plurality of electrical This can be achieved with a heating element 36. With gas or oil heating means, the object as a means of uniform heating for the purpose of successfully forming the desired chromium coating on the surface of I found out that there isn't.

Describing again the a-shaped nature of the furnace 28, it is indicated by the reference numeral 46 in FIG. 1 or FIG. A ROM coating such as a chromium coating is applied to a tubular portion such as the tubular member 44 shown in FIG. According to the invention, the following steps are preferably carried out to apply the coating to the outer circumferential surface of the material.

First, a fixed footing, such as the fixed footing 12 of a suitable molded refractory material shown in FIG. establish. Next, a plurality of support members such as the plurality of support members 14 shown in FIG. Adjacent items are placed on a fixed foundation with appropriate spacing between them. Then, preferably , a retort with a lid having a structure like the retort 16 shown in FIGS. 1, 2, and 3. , with the lid removed, place the device on top of multiple supporting members, and install it on a fixed foundation. Provide appropriate support.

The lid has been removed from the retort, allowing access to the inside of the retort. , deposit a uniform layer of powder approximately 172 inches (12,7 mm) thick on the bottom of the retort. spread it out. The powder used for this purpose is 3% ammonium chloride, 55% alumina %, in the form of a mixture consisting of 42% ferrochrome. Regarding this, the book The powder residue remaining after applying chromium coating to the surface of an object according to the invention is It is possible to reuse the powder by mixing it with approximately 25% new powder. Now , after spreading the powder layer as described above, the layer of first tubular member 44 is placed in this retort. Form on top of the bottom powder layer. However, the layers of this first tubular member 44 and Before placing this and the next similar layer of tubular members 44 into the retort, First, air is passed through the inside of each of the parts 4 and 4 with an inert gas such as argon. I'll kick you out. Furthermore, the tubular members 44 of each layer formed in the retort in this way Once the air has been expelled from the inside of each, a plug of suitable construction, preferably a plate A plug made of gold is fitted tightly into each end of each of these tubular members 44. .

Once this first layer of tubular member is formed in the retort, the bottom of the retort Spread a layer of the same powder mixture approximately 1/2 inch (12,7 mm) thick. is formed over the first tubular member layer. Following this, a layer of tubular member 44; and approximately 1/2 inch (12,7 mm) thick powder layers in the retort. As the retort continues to form, the capacity of the retort reaches its capacity to accommodate the layers of tubular member 44. , or stop when the desired number of layers of tubular members have been formed. Illustrated in Figures 2 and 3 In the embodiment of the present invention, there are six layers of tubular members 440 and 48, which are spread over the bottom of the retort. A powder layer with a thickness of approximately 1/2 inch (12.7 mm) including the powder layer 5 It is indicated by 0. The last or sixth layer of tubular member 44 in the illustrated embodiment is Once formed within the retort, this last layer 48 is placed within the retort. Powder of the same mixture as the powder layer 50 described above is deposited to a thickness of approximately 4 inches (101°6 mm). 2 to form a powder layer indicated by reference numeral 52 in FIG.

The retort is then capped and sealed by welding. Following this, Leto The inlet passage means and outlet passage means suitably formed in the retort are emptied from the interior of the retort. of a fluid medium, e.g. an inert gas such as argon, suitable for expelling air. Connected in fluid flow relationship to a source suitable for supply. Then, for example Move the furnace over the retort using a conventional industrial crane with a This allows the heating means of the furnace to connect to the tubes placed in the retort as described above. The layer 48 of the shaped member 44 can be heated. Move the furnace to a position surrounding the retort. After the movement, the inlet passage means and the outlet passage means are filled with an inert material such as argon. Connect to a suitable supply source of a fluid medium, which is a reactive gas, in a fluid flow relationship, and That is, it allows air to be expelled from the area surrounding the retort.

Heating of the layer 48 of the tubular member 44 by the furnace heating means then begins. This furnace Simultaneously with the start of heating of the layers of the tubular member by thermal means, an inert gas is introduced into the inlet of the retort. from the passage means into the interior of the retort and through the inlet passage means of the furnace; Begin to flow into the surrounding area of the furnace. The layer 48 of the tubular member 44 placed within the retort During the heating stage, fumes are generated. This hume flows inside the retort. The inert gas is transported out of the retort via the outlet passage means and further into the furnace. The inert gas flowing therein is carried out through the outlet passage means of the furnace.

Preferably these exit through the retort outlet passage means and the furnace outlet passage means. fumes and inert gases before being discharged to the atmosphere according to the illustrated embodiment of the invention. so that it flows into the chimney. This chimney is designated 54 in the drawings. Hi Once the yum begins to form, it can be applied using any conventional igniter (not shown). Please light it. The ignition of this Huyum is done by the Huyum who takes out the retort and this. This is done after leaving the enclosing furnace area, which allows Huyum to ensure that this burns before being released into the Tubular member 4 placed in a retort by heating means of a furnace Heating of the layer 48 of 4 and the furnace area disposed surrounding the retort and the retort. In this case, for example, if the chrome coating to be applied is This continues until the outer circumferential surface of the shaped member 44 is formed. The coldest point in the retort However, a first predetermined temperature of 2100°F (1135°C) is reached. Furthermore, after that A predetermined temperature of 2100°F (1135°C) is maintained for the desired 10 hours. Ru. In this regard, the chromium coating to be applied is applied to the outer peripheral surface of the tubular member 44. If not chrome coated, successfully apply a chrome coat to the surface of such other object. The predetermined temperature that should be heated to temperature, such as 2100”F (1135°C) or less and 1700°F (912°C) Temperatures may range from 2100°F (1135°C). Similarly, the tube In cases other than applying chromium coating to the outer peripheral surface of the shaped member 44, the predetermined temperature is continuously maintained. The time that should be maintained is a time other than 10 hours, for example, 10 hours or more. It might happen.

Tubular member 44 is heated to a predetermined temperature, i.e., 2100°F (1135°C); When the temperature has been maintained continuously for a predetermined period of time, i.e. 10 hours, the heating means of the furnace are turned off; and a stream of inert gas flowing through the retort and the area of the furnace surrounding this retort. The cooling of the layer 48 of the tubular member 44 placed in the retort is started. Lettle This cooling of the layer 48 of the tubular member 44 placed within the retort causes the hottest part of the retort to This continues until the cooling reaches a second predetermined temperature.

For the layer 48 of the tubular member 44 placed within the retort, this second predetermined temperature is 00'F (190°C). The chrome coating to be applied is on the outer periphery of the tubular member 44. If the chrome coating is not applied to a surface, it is possible to successfully chrome the surface of the particular object in question. This second predetermined temperature for applying the coating may be a temperature other than 400'F (190°C). It can be. The hottest point in the retort is at a second predetermined temperature of 400°F (190°C) Once the furnace has cooled down to from the position surrounding the retort. Then this furnace, the rug The retort is moved from its surrounding position by a conventional industrial crane. Melt. When the furnace is thus moved from the retort, the inlet passage means and the outlet passage means is also removed in the same way. Finally, remove the lid from its seal with the retort.

After removing the lid from the retort, any powder remaining in the retort and Bring out the eyebrows 48 of the tubular member 44 that was placed there. Then each tubular member 44 Clean to remove any powder adhering to it. Also, the required scope of claim 1 a) supporting means (12, 14); b) one or more surfaces supported on this support means (12, 14); Articles (44, 56, 5 8, 64); C) formed in the first position of this retort (16) and inside this retort (16) first inlet passage means (24) for supplying a fluid medium to the d) said first inlet passage means (2) formed in a second position of said retort (16); 4) into the retort (16) and flows through the retort (16). first outlet passage means (26) for discharging the fluid medium from the retort; e) a first position surrounding said retort (16) and said retort (16); can be moved between this surrounding position and a moved second position, and is in said first position. At the time, the retort (16) is uniformly heated to a first predetermined temperature, and then the retort (16) is heated uniformly to a first predetermined temperature. 16) heating means for maintaining uniform heating to this first predetermined temperature for a predetermined period of time; a furnace (28) equipped with (34); f) formed in a first position of this furnace (28), said furnace (28) having said first position; supplying a fluid medium into the furnace so as to surround the retort (16) when occupied; a second inlet passageway means (38) for; g) said second inlet passage means (38) formed in a second location of said furnace (28); A fluid medium supplied from the furnace (28) surrounds the retort (16). a second outlet passage means (4) for discharging from the furnace (28) after the 0) and h) said furnace (28) and said support means when said furnace (28) occupies said first position; (12, 14) and the furnace (28) and, as a result, the retort ( 16) sealing means (42) for sealing from the surrounding environment; Chrome coating on one or more surfaces of the objects (44, 56, 58, 64) Apparatus (10) for applying coverings (46, 60, 62, 66).

2. A device according to claim 1, wherein the support means (12°14) are attached to a fixed foundation (12°14). 2) A device (10) characterized in that it includes:

3. The device according to claim 2, wherein the fixed foundation (12) serves as a thermal insulation barrier. the furnace (28) and the retort (16) thereon; characterized by being formed of a molded refractory material with sufficient strength to support device (10).

4. Apparatus according to claim 3, wherein the support means (12, 14) further include A plurality of pieces arranged on the fixed foundation (12) at a distance from each other in contact with each other. A device (10) characterized in that it includes a support member (14).

5. The device according to claim 4, wherein each of the plurality of support members (14) , which can act as a thermally insulating barrier and have said furnace (28) and said Constructed of molded refractory material of sufficient strength to support the retort (16) A device (lO) characterized in that:

6. The apparatus according to claim 1, wherein the retort (16) has a removable lid ( 22) and the adjacent ones so as to give the retort (16) a box-shaped shape. A device (1) characterized in that it includes a plurality of interconnected side wall members (18). 0).

7. The apparatus according to claim 6, wherein the heating means (34) of the furnace (28) is A device (10) characterized in that it includes several electrical heating elements.

8. The apparatus according to claim 7, wherein the predetermined temperature for heating the retort is 2100. Apparatus (10) characterized in that the temperature is 1135 °F (1135 °C).

9. The apparatus according to claim 8, in which the retort (16) is heated to 2100'F ( The predetermined time for maintaining a uniform temperature of 1135°C is 10 hours. Apparatus (10).

10. Apparatus according to claim 1, in which a fluid medium is supplied to the retort (16). acts to expel air from the inside of the retort (16). device (10).

11. The apparatus according to claim 10, wherein the fluid medium supplied to the retort (16) Device (10) characterized in that the body is an inert gas.

12. The apparatus according to claim 11, wherein the inert gas is argon. Featured device (10).

13. The apparatus of claim 1, wherein the fluid medium supplied to the furnace (28) is characterized by acting to expel air from the area surrounding the retort (16) A device (10) for

14. The apparatus according to claim 13, wherein the fluid medium supplied to the furnace (28) is A device (10) characterized in that it is an active gas.

15. The apparatus according to claim 14, wherein the inert gas is argon. Featured device (10).

16 a) providing support means (12, 14); b) on said support means (12, 14); C) mounting a retort (16) with a removable lid (22) on the retort; A first predetermined thickness layer (50) of powder containing a chromium source at the bottom of the root (16) Spread it evenly, d) Chrome coating on one or more surfaces (46, 60, 62, 66) The layer (48) of the object (44, 56° 58, 64) to be treated is placed in the retort ( 16) on top of the powder layer (50); e) objects (44, 56, 58, 64) with a second predetermined thickness powder layer (52) containing a chromium source. covering, f) placing the lid (22) of said retort (16) on top of said retort (16); Seal the lever lid (22) in its proper position, g) a furnace (28) with heating means (34) surrounding said retort (16); h) sealing said furnace (28), thereby said retort (16); sealing (42) L from the environment surrounding the furnace (28); j) said retort (16) and therefore its heating means (34) of said furnace (28); Uniformly heat the object (44, 56° 58, 64) placed inside to a first predetermined temperature. start doing things, j) According to step i. A fluid medium is introduced into the retort (16) at the same time as heating starts. supply, k) allowing said fluid medium to flow through said retort (16) and then drain therefrom; Inside the furnace (28) surrounding the retort (16) at the same time as the heating of step i starts. m) supplying a fluid medium to said retort (16), said fluid medium surrounding said retort (16); After flowing through the furnace (28), it is discharged from the furnace (28); n) In uniformly heating the retort (16) to the first predetermined temperature, The object (44, 56, 58, 64) placed in the retort (16) is Continuously maintain a predetermined temperature for a predetermined time, 0) When the predetermined time has elapsed, the retort (16) and therefore the retort (16) Finish heating the object (44°56, 58.64) placed in the p) step Simultaneously with the end of heating at 0, the fluid medium flows into the retort (16) and the furnace ( 28) blocking both the flow of fluid medium to q) said retort (16) and therefore said object (4) placed in said retort (16); 4, 56, 58, 64) to a second predetermined temperature, r) said retort (16) and therefore said object (4) placed in said retort (16); 4, 56, 58, 64) has cooled to a second predetermined temperature, the furnace (28) is Remove from the position surrounding Torto (16), S) removing the lid (22) from the retort (16); t) The objects (44, 56, 58) placed in step d from inside the retort (16) , 64). , 64) on one or more surfaces of the chromium coating (46,60°62, 66).

17. The method according to claim 16, wherein the object (44, 56° 58, 64) After removing the layer (48) from said retort (16), these objects (44, 56) , 58, 64) from the layer (48). A patent featuring 18. The method according to claim 17, wherein the object (44, 56, 58, 64) of one or more of the layers (48) of the objects (4 4, 56, 58, 64). Law.

19. The method according to claim 18, wherein the chromium coating (46°60, 62.66) Shot peening the surface of the object (44, 56, 58, 64) A method further comprising the steps of:

20. A method according to claim 16, wherein the support means (12° 14) are molded. A method characterized in that it includes a fixed foundation (12) made of refractory material.

21. The method of claim 20, wherein the support means (12°14) further comprises: A plurality of supports arranged on the fixed foundation (12) at intervals between adjacent ones. A method characterized in that it includes a member (14).

22. The method of claim 21, wherein the first predetermined thickness of the powder layer includes a chromium source. (50) and chromium coating (46, 60, 62) on one or more surfaces. , 66) and the layer (48) of the object (44, 56, 58, 64) to be applied. The method further comprises the step of adding to the retort.

23. The method of claim 22, wherein the first predetermined thickness of the powder layer (50) is 1/2 inch (12,7 mm).

24. The method of claim 23, wherein the second predetermined thickness of the powder layer (50) is 4 inches (101,6 mm).

25. A method according to claim 24, in which the objects (44, 56, 5 8, 64) are tubular members, each of which is coated with chrome (46, 60, 62, 66). ) is applied to the outer peripheral surface.

26. The method of claim 25, wherein the first predetermined temperature is 2100°F (1135°F). ℃).

27. The method according to claim 26, characterized in that the predetermined time is 10 hours. How to make it a sign.

28. The method of claim 27, wherein the second predetermined temperature is 400°F (190°C ).

29. The method of claim 28, wherein the fluid medium supplied to the retort is inert. A method characterized by being a sexual gas.

30. The method according to claim 29, wherein the inert gas supplied to the retort is A method characterized by being Rougon.

31. The method of claim 28, wherein the fluid medium supplied to the furnace (28) is A method characterized in that it is an active gas.

32. The method according to claim 31, wherein the inert gas supplied to the furnace (28) A method characterized by being argon.

33. The method according to claim 32, wherein the object (44, 56° 58, 64) These objects (44, 56) are placed in the retort (16) prior to placing the layer (48) into the retort (16). , 58, 64) inside each object (44, 56, 58, 64) of the layer (48). characterized by further comprising the step of flowing an inert gas to expel air therein. How to do it.

34. The method according to claim 33, wherein the object (44, 56° 58, 64) expel air from inside each individual object (44, 56, 58, 64) of layer (48) The method further comprises the step of sealing both ends of the wafer.

35. The method according to claim 34, wherein the powder layer (50, 52), each containing 3% ammonium chloride and 55% alumina1. Ferrochrome 42 % mixture.

36. The method according to claim 16, wherein the retort (16) and the retort The layer (48) of objects (44, 56° 58, 64) placed in the tray (16) is heated. A method characterized in that fume is generated in the retort (16) as the retort is heated. .

37. The method of claim 36, wherein the fluid medium flowing within the retort (16) body, the fume generated in the retort (16) is transferred to the retort (16). ).

38. The method of claim 37, wherein the fluid medium flowing within the retort (16) After the hume has been carried out of the retort (16) by the A method further comprising the step of lighting a yum.

39. The method according to claim 16, wherein the retort (16) and the retort The layer (48) of objects (44, 56° 58, 64) placed in the tray (16) is heated. A method characterized in that fume is generated in the furnace (28) as the temperature increases.

40. The method of claim 39, in which the retort (16) is surrounded by a Due to the fluid medium flowing in the furnace (28), the fumes generated in the furnace (28) are A method characterized in that it further comprises the step of conveying the mixture out of the furnace (28). .

41. The method of claim 40, in which the retort (16) is surrounded by a The fluid medium flowing within the furnace (28) causes the fume to move out of the furnace (28). characterized by further including the step of igniting this hume after being carried to How to do it.

42 a) providing a support means (12, 14); b) on this support means (12, 14); C) mounting a retort (16) with a removable lid (22) on the retort; A first predetermined thickness of powder containing other than a chromium source is placed at the bottom of the funnel (16). Spread the layer (50) evenly, d) Object (44, 56, One or more of each object (44°56, 58.64) in the layer (48) of 58,64) apply a slurry containing a chromium source to a greater number of surfaces; e) chromium coating on one or more surfaces (46, 60, 62, 66) The layer (48) of the object (44, 56° 58, 64) to be treated is placed in the retort ( 16) Place on top of the powder layer, f) objects (44, 56, 58, layer (48) of 64) with a second predetermined thickness powder layer containing something other than a chromium source. Cover with (52), g) Place the lid (22) of the retort (16) on the retort (16). Seal the lid (22) in the correct position, h) a furnace (28) with heating means (34) surrounding said retort (16); i) sealing said furnace (28) and thereby said retort (16); j) sealing said furnace (28) from the surrounding environment; and j) heating means (3) of said furnace (28). 4) the retort (16) and therefore the object (44,56°) placed therein. 58, 64) to start uniformly heating it to a first predetermined temperature; k) Supplying a fluid medium into the retort (16) simultaneously with the start of heating in step j. supply, l) allowing said fluid medium to flow through said retort (16) and then drain therefrom; m) the furnace (28) surrounding the retort (16) at the same time as heating starts in step j; n) before this fluid medium surrounds said retort (16); After flowing through the furnace (28), it is discharged from the furnace (28); 0) In uniformly heating to the first predetermined temperature, the retort (16) and therefore the The object (44, 56, 58, 64) placed in the retort (16) is Continuously maintain a predetermined temperature for a predetermined time, p) When the predetermined time has elapsed, the retort (16) and therefore the retort (16) Finish heating the object (44°56, 58.64) placed in the q) step At the same time as the heating of p is completed, the fluid medium flows into the retort (16) and the furnace ( 28) blocking both the flow of fluid medium to r) said retort (16) and therefore said object (4) placed in said retort (16); 4, 56, 58, 64) to a second predetermined temperature, S) said retort (16) and therefore said object (4) placed in said retort (16); 4, 56, 58, 64) has cooled to a second predetermined temperature, the furnace (28) is Remove from the position surrounding Torto (16), t) removing the lid (22) from the retort (16); U) The objects (44, 56, 58) placed in step e from the retort (16) , 64). , 64) on one or more surfaces of the chromium coating (46,60°62, 66).

43. The method of claim 42, wherein the powder disposed in the retort (16) Each of the layers (50, 52) of the mixture is composed of ammonium chloride and alumina. A method characterized by:

Treasure investigation report External investigation report, -38°. 2.2,

Claims (1)

[Claims] 1 a) supporting means; b) a chrome coating on one or more surfaces supported on this support means; a retort that houses the item to be treated; c) formed in a first position of the retort for supplying a fluid medium to the interior of the retort; a first inlet passage means for; d) said first inlet passageway means formed in a second position of said retort; A fluid medium supplied to the inside of the retort and flowing inside the retort is discharged from the retort. first exit passage means for discharging; e) a first position surrounding said retort and from this position surrounding said retort; the retort when in the first position; uniformly heating the retort to a first predetermined temperature; and then uniformly heating the retort to this first predetermined temperature. f) a heating means for maintaining the heating temperature for a predetermined period of time; position, and when the furnace occupies the first position, a fluid medium is introduced into the furnace. second inlet passageway means surrounding and feeding the retort; g) a fluid formed in a second location of said furnace and fed from said second inlet passage means; Media flows through the furnace and surrounds the retort and is then discharged from the furnace. h) second outlet passage means for ensuring that when said furnace occupies said first position said interposed between the furnace and the support means, a ring surrounding the furnace and consequently the retort; and a sealing means for sealing from the boundary. A device for applying a chrome coating to one or more surfaces of an object. 2. The apparatus of claim 1, wherein the support means includes a fixed foundation. A device used as a sign. 3. The device according to claim 2, wherein the fixed foundation functions as a thermal insulation barrier. and has sufficient strength to support the furnace and the retort thereon. 1. A device characterized in that it is formed of a molded refractory material. 4. The device according to claim 3, wherein the supporting means further includes including a plurality of support members disposed on the fixed foundation at intervals from each other; A device featuring: 5. The device according to claim 4, wherein each of the plurality of support members is thermally insulated. act as a barrier and support the furnace and the retort thereon; equipment characterized in that it is formed of a molded refractory material having sufficient strength to Place. 6. The apparatus according to claim 1, wherein the retort has a removable lid and the retort. Multiple side walls interconnected with adjacent ones to give the tort a box-like shape A device characterized in that it includes a member. 7. The apparatus according to claim 6, wherein the heating means of the furnace comprises a plurality of electric heating elements. A device characterized in that it contains a child. 8. The apparatus according to claim 7, wherein the predetermined temperature for heating the retort is 2100. A device characterized in that the temperature is °F. 9. The apparatus of claim 8, wherein the retort is maintained at a uniform temperature of 2100°F. A device characterized in that the predetermined time for holding the device is 10 hours. 10. The apparatus according to claim 1, wherein the fluid medium supplied to the retort is A device characterized in that it acts to expel air from the inside of the tort. 11. The apparatus of claim 10, wherein the fluid medium supplied to the retort is inert. A device characterized by being a sexual gas. 12. The apparatus according to claim 11, wherein the inert gas is argon. Featured device. 13. The apparatus of claim 1, wherein the fluid medium supplied to the furnace is device characterized in that it acts to expel air from the area surrounding it. 14. The apparatus of claim 13, wherein the fluid medium supplied to the furnace is an inert gas. A device characterized by: 15. The apparatus according to claim 14, wherein the inert gas is argon. Featured device. 16 a) providing support means; b) mounting a retort with a removable lid on the support means; c) leveling a first predetermined thickness layer of powder containing a chromium source on the bottom of this retort; d) applying the chrome coating to one or more surfaces; placing a layer of an object on top of the layer of powder in the retort; e) adding a layer of the object placed in said retort according to step d to a layer containing a chromium source; covered with a powder layer of a predetermined thickness of 2; f) placing the retort lid on top of the retort and sealing the lid in place; g) disposing a furnace having heating means in surrounding relation to said retort; h) sealing said furnace thereby sealing said retort from the environment surrounding said furnace; death, i) heating means of said furnace heats said retort and thus said objects placed therein; Start uniformly heating to a predetermined temperature, j) supplying a fluid medium into the retort simultaneously with the start of heating in step i; k) causing the fluid medium to drain from the retort after it has flowed through the retort; l) Providing a fluid medium into the furnace surrounding the retort simultaneously with the start of heating in step i; supply, m) transferring this fluid medium from the furnace after it has flowed through the furnace surrounding the retort; n) in uniformly heating the retort to the first predetermined temperature; The object placed in the retort is heated to the first predetermined temperature continuously for a predetermined period of time. and o) after the predetermined period of time, the retort is placed in the retort. p) At the same time as the heating of step o is completed, the retort is heated. blocking both the flow of fluid medium to and the flow of fluid medium to the furnace; q) cooling the retort and therefore the object placed in the retort to a second predetermined temperature; r) the retort and therefore the object placed in the retort are moved to a second location; Once cooled to a constant temperature, remove the furnace from the position surrounding the retort, and s) t) removing the lid from the retort; t) before placing it from inside the retort in step d; Extract the layers of the recorded object Applying a chromium coating to one or more surfaces of an object comprising a process How to 17. The method of claim 16, wherein the layer of the object is removed from the retort. After that, the method further includes the step of brushing off the adhering powder from the layers of these objects. How to characterize it. 18. The method according to claim 17, wherein the layer of the object is removed after removing the adhering powder. further comprising the step of heat treating one or more of the objects. How to characterize it. 19. In the method according to claim 18, the surface of the chromium-coated object is A method further comprising the step of topeening. 20. The method of claim 16, wherein the support means is formed of a molded refractory material. A method characterized in that it includes a fixed foundation. 21. The method of claim 20, wherein the support means further comprises Composite foundations placed on the fixed foundation at intervals of A method characterized in that it includes several support members. 22. The method of claim 21, wherein the first predetermined thickness of the powder layer includes a chromium source. and a layer of the object on which one or more surfaces are to be coated with chromium. A method further comprising the step of adding alternately to said retort. 23. The method of claim 22, wherein the first predetermined thickness of the powder layer is 1/2. A method characterized by being inches. 24. The method of claim 23, wherein the second predetermined thickness of the powder layer is 4 inches. A method characterized in that 25. The method of claim 24, wherein each of the objects in the layer is a tubular member. A method characterized in that the surface to which the chromium coating is applied is the outer peripheral surface. 26. The method of claim 25, wherein the first predetermined temperature is 2100°F. A method characterized by: 27. The method according to claim 26, characterized in that the predetermined time is 10 hours. How to make it a sign. 28. The method of claim 27, wherein the second predetermined temperature is 400°F. A method characterized by: 29. The method of claim 28, wherein the fluid medium supplied to the retort is inert. A method characterized by being a sexual gas. 30. The method according to claim 29, wherein the inert gas supplied to the retort is A method characterized by being Rougon. 31. The method of claim 28, wherein the fluid medium supplied to the furnace is an inert gas. A method characterized in that 32. The method according to claim 31, wherein the inert gas supplied to the furnace is argon. A method characterized in that 33. The method of claim 32, including placing the layer of objects in the retort. First, inert gas is flowed into the inside of each object in the layer of these objects to empty it. A method further comprising the step of expelling Qi. 34. The method of claim 33, wherein the layer of objects is emptied from the inside of each object. The method further includes the step of sealing both ends after expelling air. Method. 35. The method of claim 34, wherein each of the powder layers placed in the retort contains a mixture of 3% ammonium chloride, 55% alumina, and 42% ferrochrome. A method characterized by: 36. The method according to claim 16, wherein the retort and fumes are generated within the retort as the layer of material is heated. How to characterize it. 37. The method of claim 36, wherein the fluid medium flowing within the retort and carrying out the fume generated in the retort to the outside of the retort. A method characterized by comprising: 38. The method of claim 37, wherein the fluid medium flowing within the retort igniting the fume after it is carried out of the retort. A method further comprising the steps of: 39. The method according to claim 16, wherein the retort and characterized in that fumes are generated in the furnace as the layer of the burnt object is heated. how to. 40. The method according to claim 39, wherein the inside of the furnace is in a relationship surrounding the retort. The fumes generated in the furnace are carried away from the furnace by a fluid medium flowing through the furnace. A method further comprising the steps of: 41. The method according to claim 40, wherein the inside of the furnace is surrounded by the retort. After the fume is carried out of the furnace by a fluid medium flowing through the The method further comprises the step of igniting the flame. 42 a) providing support means; b) mounting a retort with a removable lid on the support means; c) a first predetermined thickness of powder containing other than a chromium source in the bottom of the retort; Spread the layer evenly, d) one or more of each object in the layer of the object to be chromed; Apply a slurry containing a chromium source to the surface of the e) Before applying a layer of the object on which one or more surfaces are to be coated with chromium. Place it on top of the powder layer in the retort; f) The layer of objects placed in said retort according to step e is freed from anything other than a chromium source. covered with a second predetermined thickness of powder layer including; g) placing the retort lid on top of the retort and sealing the lid in place; h) disposing a furnace having heating means in surrounding relation to said retort; i) sealing said furnace thereby sealing said retort from the environment surrounding said furnace; death, j) the retort and therefore the objects placed therein are first heated by the heating means of the furnace; Start uniformly heating to a predetermined temperature, k) supplying a fluid medium into the retort simultaneously with the start of heating in step j; l) causing the fluid medium to drain from the retort after it has flowed through the retort; m) providing a fluid medium into the furnace surrounding the retort simultaneously with the start of heating in step j; supply, n) transporting this fluid medium from the furnace after it has flowed through the furnace surrounding the retort; o) When uniformly heating the retort to the first predetermined temperature, The object placed in the retort is continuously exposed to the first predetermined humidity for a predetermined period of time. p) after the predetermined period of time, the retort is placed in the retort; q) At the same time as the heating of step p is completed, the retort is heated. blocking both the flow of fluid medium to and the flow of fluid medium to the furnace; r) cooling the retort and therefore the object placed in the retort to a second predetermined temperature; s) the retort and therefore the object placed in the retort are moved to a second location; Once cooled to a constant temperature, the furnace is removed from the position surrounding the retort, and t) before before removing the lid from the retort and u) placing it from inside the retort in step e; Extract the layers of the recorded object Applying a chromium coating to one or more surfaces of an object comprising a process How to 43. The method of claim 42, wherein the powder mixture disposed in the retort is characterized in that each of the layers is composed of ammonium chloride and alumina Method.