KR910000552B1 - Manufacturing method and apparatus for semi-finished and finished products of metal, in particular steel - Google Patents

Abstract

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Description

Manufacturing method and apparatus for semi-finished and finished products of metal, in particular steel

1 is a schematic plan view of one embodiment according to the present invention.

2 is a plan view of the reducing mill shown in FIG.

* Explanation of symbols for main parts of the drawings

1: 2: Roller Conveyor

3: reducing rolling mill 4: ingot

5: manufacturing line 6: first rolling stage

6a: impact mill 7: the second rolling stage

8: Blanks 9: Core (main, final) forming processing equipment

9a: Continuous hot press 9b: Half hot press

11 frame 14: pusher

15: impact piston (plunger) 16a, 16b, 16c, 16d: caliber trestle

19: wire

The present invention relates to a method for manufacturing metals, in particular steel semi-finished products and finished products, and apparatus therefor, in particular raw materials prepared in crude or other suitable form, first heated to a hot rolling temperature in a heating furnace, and then the specific molding process The present invention relates to a method for producing a semi-finished metal product and a finished product which are rolled in a furnace.

Such a manufacturing method is used for non-cut molding of semi-finished and finished products in the molding process. The manufacture of such metal semi-finished and finished products greatly depends on the economic availability and technical suitability of the raw materials.

The production line for such metal products starts in a furnace as is known and from which the molten metal is melted and cast into ingots. The ingots produced by foundry sand casting or continuous casting are then rolled in a manufacturing history record and in a rolling mill, where the production line is usually associated with several rolling lines (rolling passages), and the final product has a length of about 30m. Rolled bars are manufactured. For further processing, a wide variety of dimensions are required from the rolling rods. Such a rolling dimensional program consists of, for example, a section of a circular or square section divided into 5 mm steps. In the dimension range of 90 to 175 mm (diameter or length) rolling mills are designed for a program series of about 15 dimensions. Such mills therefore need to prepare and retain a large number of interchangeable rollers, and in such arrangements only rolled material of the corresponding length can be machined.

Rolling programs as described above are uneconomical for individual groups, small groups, intermediate groups, and large groups of many semi-finished or finished products. The preliminary processes starting on such a milling mill have the disadvantage that the whole process has to be adapted to mass processing because bulky ingots require processing of a large amount of molten metal. Such a method is only possible for a relatively long time, as is known, and switching mills to different dimensions extends the time depending on the availability of the raw materials. Such dependence on large batch jobs and the difficulty of switching to modified dimensions delays the supply to the next manufacturing process. Particularly, in the molding step, it is required to divide the diameter of the raw material into small and precise subdivisions. In the production of such semi-finished and final products, the production of raw materials in the conventional rolling apparatus is no longer welcome from the technical and economical point of view as described above.

The object of the present invention is to enable the conformation of the workpieces in successive major deformation processes to reduce the inventory of raw materials, to suit the material demands of the continuous continuous processing process, and to adjust the raw materials for the molding process. To ensure dimensions, tolerances and precision.

It is a further object of the present invention to provide raw materials and intermediate products for the continuous processing step forming process, with particular consideration to optimize the production of the intermediate steps of the individual, small, intermediate and large groups of the overall production process. To ensure or enable supply.

According to the invention, a raw material consisting of a rollable ingot to be cut to a relatively short length and having a circular or polygonal uniform starting section is heated to a constant temperature in a heating furnace of a reducing mill and then the same. Intermediate products produced immediately before the rolling by blanking the blanks for core shapins (main molding), such as stretching and pressing, with a slightly smaller dimension than the starting cross-section. The object of the present invention can be achieved by core molding using the residual heat of. The present invention makes it possible to standardize the dimensions of the ingot to just a few uniform sizes, regardless of the geometry and size of the raw material and the finished product. Therefore, the inventory of raw materials can be reduced by several ingots (bars, billets, etc.). The workpiece to be machined (the shape of a block moja pudding ball) requires a relatively short ingot of 1 meter or less. Thus, the manufacture of such a work piece to be operated is usually very expensive and eliminates the need for expensive rolling equipment that is difficult to operate at the time of conversion. The present invention has the advantage that, among other things, it can be produced from multiple starting dimensions from several starting dimensions for individual workpieces. Thus, for example, a crude product for core molding having a diameter of 152 mm is manufactured from a uniform uniform starting material having a diameter of 175 mm, and a crude material for core molding having a diameter of 130 mm from a workpiece having a diameter of 150 mm is manufactured. From the workpiece having a diameter of 135 mm, a crude material for core molding having a diameter of 115 mm is produced. Thus, with the three dimensions (175, 150, 135 mm) in accordance with the method of the present invention, it is possible to cover the diameter range of the crude product from 175 mm to 115 mm for the core molding process. It is therefore produced with a number of application dimensions for the preparation from a few uniform starting sections.

This method provides suitable dimensions and tolerances for economic and continuous core forming reprocessing in terms of inventory of starting materials. This method is also advantageous and is one of the features of the present invention because the pre-formation of the relatively short workpiece to be exited from the furnace takes place under only one temperature by means of the reducing mill and core forming.

The principle of pre- and shooter reshaping of the workpiece to be machined now offers the possibility of producing the workpiece to be machined economically, technically and in a short time. Accordingly, the present invention is designed to be used as an ingot to be rolled into a rollable continuous casting cut to length. Therefore, the production of the ingot to be processed at this time is carried out through the melting furnace and continuous casting equipment. According to the present invention, the principle of diameter stepping of raw materials with narrowly divided steps may be applied to continuous casting equipment. Given the current economics, it is not desirable to manufacture many different dimensions in continuous casting plants. In order to program castings with such a wide variety of dimensions, the molds of round metal rods will often need to be replaced, which will greatly increase the price of the product and limit the short processing and availability of raw materials.

It is advantageous to suppress welding and forging of the dense core part of continuous casting in a reducing mill and to select a small degree of deformation in order to form the workpiece, that is, core forming, by continuous casting. In addition, the process of the reducing mill ensures the necessary round finish of the continuous casting material. The continuous casting material has a relatively large oval shape and a considerable allowable range (for example, 6 mm at a median diameter of 175 mm) for a constant molding process. Have

The manufacturing method enables the use of a uniform circular continuous casting rod without having to pass through a large rolling apparatus.

In the continuous casting of metals, especially steel, the edges and the core shall be taken into account when reworking the semifinished or final product. Therefore, the continuous casting cut to length in the direct casting process is advantageously injected at a casting speed of about 0.6 to 4m / min. The manufactured product may be usefully used for all objects manufactured by axisymmetry. In this casting speed, a material is produced that can be changed into the desired structure when properly molded.

The prestrain can be limited so that the uniform starting cross section of the workpiece to be machined is reduced by up to 80%.

It is advantageous for the core forming process to be made in a continuous hot press system for a particular manufacturing part in the manufacture of a vehicle, in particular in the manufacture of a vehicle.

The present invention can also be applied to other fields in a method in which core forming is performed by wire rod rolling.

In many different molding processes, the properties of the preparation for core forming are very important for useful semifinished and finished products. For this case, after shrinking, additional rolling steps are passed before core forming to straighten the crude material, remove scales, planarize the surface, and determine the final dimensions.

Such properties always show special importance for the forgings and for the moldings that are processed in the moulds.

The present invention can be directly applied for specific weight conditions related to strength properties. This is when the crude material is molded into axle bridges, axle tubes and axle bodies of automobiles through a forging process in continuous core molding.

The equipment for carrying out the method of the present invention is based on the fact that a manufacturer who manufactures a semi-finished or finished product by molding technology does manufacturing without a furnace. This facility is then followed by a first rolling step in the furnace for heating the workpiece to be machined in the manufacturing line, which is then descaled, straightened and smoothed after the first rolling step. The second rolling step for determining the final dimension is configured to be connected. Such facilities typically omit or substitute known known infiltration processes and make it possible to link the processing processes closely to the continuous casting process. The facility also made it possible to significantly reduce the inventory of raw materials (thus reducing inventory costs and shortening the process time). In addition, the facility can significantly shorten the delivery time compared to the necessary conversion work according to the extensive rolling program of the rolling processes as described above.

Another advantageous feature of the importance of the molding technique is the installation of a high pressure water descaling plant before the first rolling stage. This equipment is effective in removing the primary scale in the furnace, thereby allowing the raw materials to be independent of the time spent in the furnace.

The heating furnace also comprises a rotary heating furnace. Such furnaces can be designed to the desired capacity of the entire installation.

According to another feature of the invention the first rolling step is composed of one impact mill. Thus, the first rolling stage is adjusted to the required energy demand of the preforming stage. The impact mill has a cylinder roller that is not driven elsewhere, so the roller driving energy is saved.

The application field of the first rolling stage is equipped with a roller conveyor (roller track) disposed in parallel with the manufacturing line in the first rolling stage in accordance with the reduction in the preliminary inventory divided into only a few dimension stages made in accordance with the present invention, The first rolling stage and the roller conveyor can be improved and developed to move vertically with respect to the completion line. Thus, if one dimension step does not require reduction, the first rolling step can be removed from the rolling line.

According to another feature of the invention the second rolling stage is composed of a twin rolling mill. This double rolling mill can give a geometrical adaptation to the molding process, and also has the advantage of manufacturing a cone of the desired crude. In addition, the twin-roller serves to precisely test the diameter of the preparation for core (main) molding processing.

In addition, the present invention can be used in circular cross-section and polygonal cross-section, ie, coarse metal rods. To this end, the second rolling step is made of a polygonal section rolling mill.

For suitable product varieties of molding techniques, continuous core forming is preferably composed of hot presses.

In order to improve the quality of the surface of the shell used in the core forming process, continuous core forming is preferably composed of a semi-hot press. This half-hot press reduces consumption (volume of material, waste, etc.). The half hot press has other characteristics of improving the dimensional stability and tolerance of raw materials and products.

In terms of the installation method to reduce the installation cost, the impact mill has several caliber trestle (gauge die) installed in the completion line. This type of installation expands the range of use of the installation.

The caliber trestle can be easily exchanged and is a precision stand between idler and passageway. Thus, exchangeability has the effect of preventing time wastage when the large rolling mill is switched.

An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the embodiment of FIG. 1, the furnace 1 consists of a rotary furnace 1a, which is connected to the reducing mill 3 at an appropriate distance past the roller conveyor 2. . The raw material consists of ingots 4 to be processed, which are heated to a temperature of 1330 ° C. The ingots 4 have a length of up to 1000 mm in this embodiment. The ingots 4 to be processed are made from rolled or direct cast material and have a corresponding material structure. The furnace 1 and the reducing mill 3 are located on one manufacturing line 5. The reducing mill 3 forms a first rolling stage 6, and the second rolling stage 7 is connected to another roller conveyor 2a and is located on the manufacturing line 5. The second rolling step (7) serves to straighten and straighten the ingots (4), remove scales, flatten the surface, and complete the final dimension. In this case, the ingots (4) are uniformly stretched and have an outer diameter. It is made of crude material 8 with reduced dimensions. The crude material 8 is sent to the core forming process 9 by the following roller conveyor 2b.

The high-pressure water descaling device 10 for removing the primary scale of the rotary furnace 1a is installed in front of the first rolling step 6.

The first rolling stage 6 consists of an impact mill 6a (shown in detail in FIG. 2). The exception is that the uniformly rounded or polygonal cross section of the ingot 4 is not preformed, and the rolling device group 12 of the first rolling step 6 has a side roller conveyor 13 on its own support frame 11. And the rolling device group 12 can be moved laterally from the manufacturing line 5, and the side roller conveyor 13 can be moved laterally from the manufacturing line 5 together with the conveyor line 13a. The side roller conveyor 13 can be shifted to the manufacturing line 5 together with the conveyor line 13a. The second rolling stage 7 is formed of a double-spinning mill 7a and consists of a polygonal diameter rolling mill 7b for the polygonal cross section of the ingot 4 to be processed. In order to manufacture axle bridges, axle tubes, axle bodies, etc. of automobiles, the core forming apparatus 9 is composed of a hot press 7a. In the case where the ingot 4 to be processed has special properties, the continuous half hot press 9b is provided instead of the continuous hot press 9a.

The impact mill (6a) (FIG. 2) has a bar ingot (14), which is formed by the impact piston (15) on the preheated ingot (4) placed on the roller conveyor (2). Push into the rolling stage (6). Important here is the group 12 of caliber trestle 16a, 16b, 16c, 16d that is not driven. Each caliber trestle consists of three rollers. It is possible in principle for each caliber to use two to four rollers or to increase or decrease the number of calibers. Each caliber trestle is easy to replace from above (figure 2). To this end, the frame 11 forms one cassette and is composed of side frames 11a and 11b and transverse frames 17a, 17b and 17c, which are coupled to each other by anchor bolts 18. At the end of the cassette, a wiper 19 is provided to shake off the molded crude 8.

The method is particularly suitable for producing continuous press aids to be molded into axle bridges, axle tubes and axle bodies of motor vehicles. The crudes 8 are here produced by thermal deformation in the mold of the core forming process 9 (continuous hot press 9a, continuous semi-heat press 9b), ie by hot forming in the composite forward and reverse continuous presses. .

The continuous press itself is not a subject of the present invention. Instead of the hot press 9a and the half hot press 9b, different core forming processes may be performed respectively.

According to the method and apparatus of the present invention, even very short ingots can be accurately reduced in diameter, which was not possible in the conventional rolling reduction method. Shorter ingot length has the effect of improving furnace utilization of the furnace.

In the first rolling stage 6 (reducing mill 3 and the second rolling stage 7 (caliber rolling mill)) to reduce the rolling of the ingot 4 to be processed, STE43, STE47, ST52, 16MnCr ₅ and all other rollables It is possible for intermediate molding to reduce the material and direct continuous casting material from 175 mm in diameter to 145 mm in diameter, for example.

The following is an application of the method of the present invention.

[Example Ⅰ]

Continuously cast ingots with a diameter of 175 mm and a length of about 400 to 650 mm can be used as ingot materials for all kinds of axle bridges. The quality F47S2, F43 / 9, F43 / 4 and S52 are used here. The ingots are made of conventional dimensions of 170, 165, 160 and 155 mm diameter for the second rolling step 7, and continue to pass through the processing step without any obstacles.

[Example II]

Circular axle bodies of diameters 145 mm, 150 mm, 155 mm and larger diameters can be made from continuous cast ingots of diameter 175 mm. All current axle body materials can be impact rolled.

[Example III]

Hexagonal axle bodies having a corresponding dimension between 173 mm and 150 mm in diameter are suitably divided into corresponding steps, and can be molded into a hexagonal axle with impact rolling in a continuous press process and an edge dimension (diameter) of 120 to 155 mm.

[Example IV]

Ingots for axle tubes having a starting dimension of 95 to 140 mm in diameter can be made from several ingot dimensions using the method of the present invention. As raw materials it is possible to use rolled prototypes and corresponding continuous casting dimensions which can be provided.

As described above, according to the present invention, it is possible to formally conform the workpieces in the main core forming process, to simplify inventory of raw material ingots, and to ensure the accuracy of dimensions, errors, and shapes of raw materials. have.

Claims (19)

The ingot is heated using a relatively short rollable ingot of uniform circular or polygonal cross section, and the heated ingot is made of a crude material of only slightly smaller than the original section using only the residual heat of the ingot supplied in the heating step. A method of producing semi-finished and finished steel products for subsequent major core forming operations, which is configured as a step of rolling down without further heating and rolling continuously without further heating. The method of claim 1, wherein the ingot is manufactured by continuous casting. The method of claim 2, wherein the continuous casting is made at a casting speed of 0.6-4 m / min. The method of claim 1, wherein the pressing reduction step is reduced to a maximum of 80%. The method of claim 1, wherein the main core processing is hot or semi-hot press. The method of claim 1, wherein the main core processing is a steel semi-finished and finished product by a wire rod rolling process. The method for manufacturing a semi-finished steel product and finished product according to claim 1, which comprises a rolling step for descaling, straightening, surface leveling and sizing before core forming after the reduced rolling process. 8. The method of claim 7, wherein the core forming process is performed by a forging method. Heating furnace (1) heating relatively short raw material ingot to rolling temperature (1) From the first rolling step (6), the first rolling step of reducing and stretching the outer diameter of the ingot at the position directly connected to the heating path A second rolling step (7), which is arranged in the lower (downstream) line and performs descaling, processing, surface leveling and final dimensional processing without additional heating intervening; A device for supplying core forming process (9) is provided, and metal, in particular steel semi-finished and finished products for preparing coarse forming preparations which are directly combined with the above (upstream) process from core forming process (9). Manufacturing equipment. 10. The apparatus for manufacturing semi-finished and finished steel products according to claim 9, wherein the high-pressure water descaling device (10) is provided in front of the first rolling step (6). 10. The apparatus according to claim 9, wherein the heating furnace (1) is a rotary furnace (1a). 10. The apparatus of claim 9, wherein the first rolling step (6) is an impact rolling mill (6a). 10. The roller conveyor (13) is installed parallel to the first rolling step (6), and the roller conveyor (13) is switched in place of the first rolling step (6) in the manufacturing line (5). Manufacturing equipment of mobile steel semi-finished and finished products. 10. The apparatus for manufacturing semi-finished and finished steel products according to claim 9, wherein the second rolling step (7) is a double-rolling mill (7a). 10. The apparatus for manufacturing semi-finished and finished steel products according to claim 9, wherein the second rolling step (7) is a polygon sizing rolling mill (7b). The apparatus for manufacturing semi-finished and finished products of steel according to claim 9, wherein the core forming process (9) comprises a continuous hot press (9a). 10. The apparatus for manufacturing semi-finished steel products and finished products according to claim 9, wherein the core forming process (9) comprises a continuous semi-heat press (9b). 13. Apparatus according to claim 12, wherein the impact mill (6a) has a plurality of caliber trestle (16a, 16b, 16c, 16d). 19. Apparatus according to claim 18, wherein the caliber trestle (16a, 16b, 16c, 16d) is easily replaceable.

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