JPS59212251A - Components with ceramic coating layer - 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 [Field of Application of the Invention] The present invention relates to a coating composition for significantly improving the heat resistance, distribution properties and corrosion resistance of products made of superalloys based on Ni, Co and Fer. It is about things.

[Background of the invention]

For products used under 31% product conditions, in addition to improving the oxidation and corrosion resistance of the parts themselves, ensuring that the temperatures of the parts themselves do not get too hot increases the reliability of the product and extends its lifespan. This is important when measuring. Especially 800-1200t? Various technologies have been developed for products such as gas turbine 7J blades, nozzles, and liners that are used under these high-temperature conditions, with the aim of improving their reliability and extending their service life. One effective method for reducing the temperature of the member itself is to coat the surface of the member with a material that is stable at high temperatures and has low thermal conductivity and high load resistance. A ZrO-based material is used as a material that satisfies these properties. ZrO! In parts made of gold-based materials, the temperature of the part itself decreases, resulting in improved product reliability and longer life.

However, the problem with such ZrO2-based material-coated members is that ZrO2-based materials can be repeatedly started and stopped over a long period of time. Peeling of the gold material layer,
This is due to falling off. Such damage to the coating layer of the Zr0.1-based material results in the loss of the effect of reducing the temperature of the member. There are various factors that cause such damage, but among them, heat generated by the difference in thermal expansion coefficient between the ZrO-based material and the heat-resistant alloy steel (hereinafter referred to as the base material) that makes up the member. Stress damage is the most dominant. Damage caused by e)? One way to prevent this is to form an intermediate layer between the ZrO2-based material coating layer and the base material. In particular, many methods have been used to form an intermediate layer r made of a mixture of a metal alloy material and a ZrO-based material in order to alleviate the difference in coefficient of thermal expansion. However, such a middle class? The problems when forming
Metal alloy material and ZrO.

Examples include the interface between the ZrO-based material and the metal alloy material in an intermediate layer that is a mixture with the ZrO-based material. Known metal alloy materials and ZrO-based materials differ greatly in physical properties such as crystal structure, molten metal content, specific heat, and vapor pressure. Therefore, even when a mixture layer of two components with completely different physical properties is formed using any method such as vapor deposition, sputtering, thermal spraying, etc., the bonding at the interface between the two components will be in a markedly mismatched state. become. Incidentally, the coating layer of ZrO2-based material formed on the outermost surface of the member is preferably porous with a porosity of a few chills to a few lo% in order to alleviate the thermal reaction occurring within the layer. Therefore, high-temperature oxidation and high-temperature corrosion penetrate into the interior through the ZrO-based coating layer that is the outermost layer. As a result, in the mixture layer, which is originally composed of a metal alloy with high Takagata resistance and high temperature corrosion resistance, and a ZrO-based material that is stable at high temperatures, the metal alloy in the layer is This prevents defects at the interface between the ZrO material and the ZrO-based material, making it easy for oxidation and corrosion to occur in that area. In particular, the mechanism of oxidation and corrosion at the interface between the chemically stable ZrO-based material and the chemically unstable metal alloy material is complex and has not yet been fully elucidated. Therefore, the conventional ZrO-based material-covered member, which has an intermediate layer with the aim of alleviating the difference in thermal expansion coefficient between the base material and the ZrO-based material* + the coated layer, has no effect on the difference in thermal expansion coefficient. The purpose of preventing the damage caused by the high temperature oxidation in the intermediate layer is not necessarily sufficient, so the oxidation of the intermediate layer,
As the corrosion progresses, the strength of that part decreases, and the coating layer peels off or falls off from the intermediate layer.

[Purpose of the invention]

The present invention has been made in view of the above points, and when forming a ZrO, thread material coating layer, Zr02
Development of a metal alloy that reduces the difference in thermal expansion coefficient between the base material and the base material, and has excellent high-temperature oxidation resistance and high-temperature corrosion resistance.
The ZrO2-based material coating layer is less likely to be damaged, and the reliability of the component even when wet is improved by +4J, and the service life is extended. This is the purpose.

[Summary of the invention]

Therefore, the present inventors investigated metal alloys in which various additive elements and associative elements were added to MCrA4 alloys with various composition ranges (M is Ni, 10 Coi/) or a combination thereof). We have found a metal alloy that has excellent high-temperature oxidation resistance and high-temperature corrosion resistance, and can serve as an intermediate layer that relaxes the coefficient of thermal expansion '9 Mk between the ZrO2-based material coating layer and the base material.

In other words, we focused on the fact that a material coated with ZrO7-based material is used under both temperature conditions, and instead of an intermediate layer consisting of a mixture of a metal alloy material and a ZrO-based material, it is possible to provide high-temperature oxidation resistance and high-temperature corrosion resistance. The entire intermediate layer is made of a mixture of alloy materials with excellent properties and metal elements that easily combine with oxygen under high width conditions and easily form oxides. Metal elements that easily combine with oxygen in such an intermediate layer become oxides under high width conditions,
By gradually forming oxides with a small coefficient of thermal expansion in this way, the coefficient of thermal expansion of the intermediate layer itself changes, and as a result, the relationship between the intermediate layer i1: Z r O, based material coating layer and the base material changes. This will alleviate the difference in thermal expansion coefficient. On the other hand, the interface between the oxide in the intermediate layer formed in this way and the base metal is originally a metal-gold@c) bonding interface. The metal-oxide junction interface VC has become the enemy. The details of this phenomenon of interface change are not clear. However, it is thought that the metal-to-metal interface in the intermediate layer before salt oxidation is also bonded via a very thin oxide film. Such a state is noticeable in a coating layer formed by a method such as plasma spraying. Therefore, at such an interface, when the metal with a stronger bonding force with oxygen becomes an oxide, the negative part of the C9x oxide present on the surface of the other metal with a weaker bonding force with oxygen will change. It is thought that it also has a reducing effect. In addition, compared to the metal-oxide interface of the known intermediate layer made of a mixture of metal and oxide, which is in a mismatched state, the metal-oxide interface of the intermediate layer of the present invention is in a paulownia-metal state. It is a change of a highly consistent interface,
This is a highly consistent metal-oxide interface. As a result, the intermediate layer of the present invention can avoid the high-intensity oxidation of the intermediate layer caused by the incompatibility of the metal-F+'<compound interface, which has been a problem with conventionally known intermediate layers. , high temperature corrosion? It becomes preventable. Such an intermediate shaft of the present invention? Zr is suitable as an element that easily combines with oxygen in the constituent materials. Zr is At, Cr, Ti
It is easier to combine with oxygen than other materials, and the formed oxide (
Zr02) is similar to the ZrO-based material that is the coating layer on the surface of the intermediate layer. Further, the metal alloy material to be mixed with Zr is required to have high temperature corrosion resistance and high temperature oxidation resistance.

As a result of the inventors' studies on various alloy components, 5
~50 wt% Cr, 3~30 wt% At, 0.01~5
It is clear that TiC is superior to alloy components in which the balance by weight of Y is at least one selected from Ni, Co, Fe, and mixtures thereof. In addition, Mn, W, Si, Hf are included in the base metal having the above component range.
, Zr, etc. may be included. Furthermore, there is no problem in adding rare earth elements other than Y. In the intermediate layer of the present invention, the mixing ratio of Zr is important. The most desirable method is to form a coating layer of the above-mentioned scrap metal alloy on the surface of the base material, then form a layer of a mixture in which the mixing ratio of Zr is gradually changed, and to form a layer of ZrO2-based material in the area in contact with the covering layer. What is the mixing ratio of Zr on the surface of a certain intermediate layer? Maximize it. In this case, it is desirable that the mixing ratio of Zr is gradually increased from 0% by weight to a maximum value of 30% by weight or less. When Zr2 is mixed with 30 weights or more, Z
rO.

The amount of formation increases, and the mechanical strength of the intermediate layer itself decreases, causing damage to the coating layer. On the other hand, it is also effective to form an intermediate layer with a constant mixing ratio, and in this case, it is desirable to set the mixing ratio of Zr to 3% by weight or more and 30% by weight or less. Although there is no particular limit to the method for forming the intermediate layer of the present invention, it is desirable to use a plasma spraying method from the viewpoint of economic efficiency of the construction method. In the case of plasma spraying, there are many fine defects in the coating layer that is formed, and internal oxidation tends to proceed on top of these fine defects, causing Zr in the intermediate layer to heat up to high temperatures. Under certain conditions, it becomes preferable for converting to ZrO□. Hereinafter, as an example, a method of forming by plasma spraying will be described in detail. The thermal spraying method used to coat the surface of the base material with the aforementioned metal alloy gold is RL+
It is preferable to carry out the process in a discretionary atmosphere with a VC resistance of less than 2 elemental partial pressures of 0-1000-1000 ml.
It is desirable to conduct the coating at a temperature of about 12,000 in order to obtain a dense coating layer with few defects. Next, the intermediate layer of the present invention is formed on the surface of the metal alloy layer. There is no particular limit to the conditions for forming the intermediate layer, but it is preferable to use the same method as for the metal alloy described above. As the Zr thermal spraying material, it is also possible to use ZrH2(]l- in addition to Zr, and in either case, there are no particular restrictions on its purity etc., and commercially available pure turtle materials may be used. The material and the metal alloy material may be mixed with powder in advance, or the materials may be mixed and then thermally sprayed.There are no particular restrictions on the thickness of the intermediate layer formed in this way. However, a range of 0.05 mm or more and 0.30 mm or less is desirable.If it is less than 0.05 mm, the effect of mitigating the difference in thermal expansion coefficient r will be small, and if it is more than 0.30 twrn, the residual stress generated in the intermediate layer will be reduced. After the intermediate layer sound of the present invention is formed in this manner, ZrO is applied to the surface of the intermediate layer sound.
.

Form a coating layer r of type material. There are particular restrictions on the thermal spraying method.
However, since the melting point of ZrO and thread material is still low, %50I
(It is desirable to use a high-output frisma of W or higher to make a single shot. Also, as ZrO-based materials, Cab, MgO
It is preferable to use a stabilizer containing 5% of Y2O.

[Embodiments of the invention]

Next, examples of the present invention will be described.

Example 1 The surface of a structural member made of Ni-based heat-resistant steel was cleaned, and the surface care alumina grid was removed and plasted. Thereafter, a 20% Cr-15% At-0.5% Y-balance Ni alloy powder was plasma sprayed. The output of one plasma injection is 40KW. With VC like this, a coating layer with a thickness of 0.05? Immediately after forming, the alloy powder and Zr
Mixed powder of powder (mixing ratio of Zr 15 parts ii:'l'i
Thermal spraying was carried out under the same conditions as for the metal alloy material described above. child(/]
In this manner, an intermediate layer having a thickness of 0.10 mm was formed, and immediately thereafter, Zr02-8% Y2O3 powder was melted.

The output of plasma spraying is 55KW'''C.In this way, 0.30111m thick 2+Zr02-8%Y2O3
A coating layer was formed.

Is the middle layer of the present invention formed as shown above? has Zr
The results show the property I' of the O2-based coating member.

Table Test Method This is a thermal cycle test in which holding at each temperature of Fi900c and 1 soc is repeated. In the table, sample A1
．． A2 is a known ZrO2-based coating member used for comparison, Al is a combination of a metal alloy layer and a ZrO2-based material coating layer (Fig. 1 (a)), and A2 is a combination of a metal alloy material and a ZrO2-based material coating layer.
, which was used as an intermediate layer in the mixture ff7' with a type material (FIG. 1(b)). As a result, ZrO with the intermediate layer of the present invention shown in Figure (C) was obtained.

The durability of the member coated with Z r 02 type material is approximately 50 to 100 times greater than that of the known member coated with Z r 02 type material.

Example 2 A metal alloy layer r having the same alloy composition was formed on the surface of a heat-resistant 13@ member made of Ni-based heat-resistant alloy steel in the same manner as in Example 1. Thereafter, an intermediate layer made of a mixture of the metal alloy material and Zr was formed while gradually changing the mixing ratio of the metal alloy material and Zr. In other words, Z gradually increases from the part in contact with the metal alloy layer.
Increase the mixing ratio, Z r Ot 8% YtO
The mixing ratio of Zr in the surface portion of the intermediate layer which is in contact with the s-covering layer was changed to 30% by weight. Thermal spraying of such an intermediate layer was carried out by separately feeding the gold 4 alloy powder and the Zr powder into the plasma jet and changing the feed material. After that, Z
A coating of rO□-8% Y2O3 was formed. Like this 3
The thickness of each coating layer of the ZrO, -8% Y2O3 coated member is the same as in Example 1. The performance test results of the members thus produced were approximately equal to or better than the results of the member of Example 1 in the table, and were excellent in durability.

[Brief explanation of drawings]

No. 11g1 is a schematic folded view of an embodiment of the Z r 02 material coated member of the present invention. 1... Member, 2... Metal alloy layer, 3... ZrO,
Hardening of materials

Claims (1)

[Claims] 1. In a component made of heat-resistant metal alloy steel, the component has a metal alloy layer on its surface that is more resistant to vortex oxidation and high-temperature corrosion than the heat-resistant metal alloy material; A member having a ceramic coating layer on its surface, comprising an intermediate layer r made of a mixture of the metal alloy material and Zr, and a ceramic coating layer on the surface of the 11J layer.