JPH0328981B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for manufacturing metal clad plates, and particularly to a method for manufacturing thin clad plates that are difficult to manufacture by hot rolling. (Prior art) The lower limit of the thickness of a metal plate that can be manufactured by hot rolling is determined by the temperature drop of the rolled material.
For steel and industrial pure titanium, the lower limit of the thickness is approximately 3 mm. Furthermore, as a method for obtaining a thinner plate by hot rolling, a method in which materials are folded or overlapped and rolled is known. It is difficult to roll a clad plate to a thin thickness, not only by hot rolling but also by cold rolling, since warpage and joint failure occur.
It is conceivable to fold the clad plates as they are or to stack them and roll them, but if this is done, good results cannot be obtained due to the difference in cooling rate between the outer layer and the inner layer. Attempts were made to reheat and reroll the cladding material, which had been previously produced by hot rolling, to the ultimate thickness, but it was found that during reheating, substances such as carbides, intermetallic compounds, and diffusion layers that could cause destruction were removed. As metal combinations are developed, it is necessary to apply large pressures to finely disperse them, but due to the rapid temperature drop, satisfactory results have not been achieved. (Problems to be Solved by the Invention) An object of the present invention is to provide a method for easily obtaining a thin clad plate with a high yield. A second object of the present invention is to provide a method for obtaining a thin clad plate with excellent dimensional accuracy, plate shape, and processing performance. (Means for solving the problem) The gist of the present invention is to
Insert the two sheets of cladding material, weld the periphery of the two base materials to form a sandwich-like assembly, and heat-roll the assembly to join the base material and the cladding material. The plates are overlapped and covered with a covering material made of substantially the same material as the base material, and these are fixed to obtain a reassembled body.The reassembled body is heated and rolled, and then the periphery of the obtained reassembled rolled material is cut. The present invention relates to a method for manufacturing a thin-walled clad plate that is characterized by peeling. For example, as shown in Figure 1, the technique of producing a clad plate by the initial hot rolling is a covering material in which a base material 1 is overlaid with a laminate material 2, and the periphery is welded in advance to accommodate the laminate material. 3 is superimposed on this, and the covering material 3 is fixed and sealed to the base material 1 by fillet welding 8. During this fillet welding, it is preferable to blow an inert gas such as argon or helium through the nozzle 9 in order to avoid contaminating the surfaces to be joined with weld fume. If the cladding material is not an active metal and the base metal and the cladding material can be directly welded, the covering material 3 can be omitted and the cladding material can be fillet welded directly to the base material. The base material 7, laminate material 6, and covering material 5, which were assembled in the same manner and have approximately the same dimensions, are placed together using a separating agent so that the laminate material is inside as shown in Fig. Weld 12. Planned joining surface 11
After reducing the pressure in the space formed by the nozzles 9 and 10, the nozzles are closed, and the surface to be joined 11 is prevented from being contaminated from the outside. This assembly is heated to a predetermined temperature, the surfaces 11 to be joined are joined by rolling, and the assembly is reduced to the thickness limit. The clad plates thus obtained are cut into appropriate lengths, stacked on top of each other, preferably while maintaining the initial sanderch structure, and assembled using substantially the same material as the base materials 1 and 7 as a covering material. Obtain reassembly materials. That is, FIG. 2 is a longitudinal section of the reassembly, and FIG.
The figure shows the same cross section, and shows cladding materials 13, 13', 1 of sandwich structure manufactured by rolling.
3" and weld the base materials together at their ends (14), or weld the base material and the covering material 15 at their ends (16), or
5 and the covering material 15' are assembled together by welding their ends to obtain a reassembled material. The structure of this reassembled material is not particularly limited as long as it can withstand rolling, but it is essential to cover the upper and lower surfaces with the covering material 15, and this requirement prevents the temperature from decreasing during transportation and rolling. Since the covering material itself has a thickness, the inner cladding material can be rolled to an even thinner thickness. In FIG. 2, three sets of cladding members with a sanderch structure are included, and the cladding plates 13, 13', 13'' have a position 12' corresponding to the first assembly welding part 12. If rolling is performed using this position as the front and rear ends, the abnormally deformed portions at the front and rear ends will be included in this part, and the length of the laminate material to be cut off as a crop can be reduced.In the method of the present invention, the base material and the laminate material By finishing the final pass rolling at a temperature equal to or higher than the recrystallization temperature, both materials start recrystallization, and the softening annealing time before cold rolling can be shortened or the softening annealing can be omitted. In the invention method, by covering the cladding members 13, 13', and 13'' of the sandwich structure with the covering material 15, it is possible to obtain the insulation effect of the covering material, and also to make it thicker by the thickness of the covering material. In addition, by increasing the rolling finishing temperature of the clad material and slowing down the cooling rate, recrystallization of the clad material and base material can be promoted and softened. After hot rolling, the surrounding area is cut to make the product, or
When covering materials 3 and 5 are used as in the example shown in FIG. 1, they are removed by pickling or grinding to produce a product. When performing cold rolling in the method of the present invention,
Normal annealing, pickling, etc. can be performed, but
By omitting this, cold rolling is limited to only the function of sheet thickness and shape adjustment, and thickness reduction is kept to a minimum range, for example, a rolling reduction of 50% or less. When covering materials 3 and 5 are used as in the example shown in FIG. 1, they are finally removed by pickling or grinding. By omitting pickling before cold rolling, dehydrogenation heat treatment can also be omitted at the same time. By leaving the covering materials 3 and 5 in place until after cold rolling, the clad materials 2 and 5, which are difficult to process, can be removed.
6 is not exposed on the surface, and the laminated material can be protected from oxidation and roll scratches. (Example) Table 1 shows examples. In Example 1, a titanium clad steel sheet having a thickness of 0.49 mm was obtained as hot-rolled, and after pickling to remove the covering materials 3 and 5, the thickness became 0.48 mm. This thickness is significantly thinner than the conventionally available thickness of 2 mm. Even without heat treatment, the titanium clad steel sheet gave good results in a close contact bending test based on JIS Z 2248. In Example 2, a 0.49 mm titanium clad steel sheet was obtained as hot rolled, and after cold rolling to a thickness of 0.32 mm without any annealing, pickling, or dehydrogenation annealing, the covering material 3 was formed by pickling. , 5 were removed.
This titanium clad steel sheet is also cold rolled and JIS
The results of the close bending test based on Z 2248 were good. The hot finishing temperature of Example 2 is estimated to be 730°C at the location of the sand German steel plate, which is about 500°C for recrystallization of steel and about 600°C for industrially pure titanium.
It has been confirmed that processing was completed at a much higher temperature, recrystallization began, and softening occurred.

【table】

[Table] (Effects of the Invention) As described above, the method of the present invention has made it possible to produce extremely thin clad plates by hot rolling. Furthermore, by cold rolling the thin clad plate thus obtained as a raw material, it has become possible to manufacture an even thinner clad plate. These effects are due to the use of the covering material. In addition, by retaining the initial sandwich structure as the material for the reassembly material and making the direction of the joining position of the base materials the front and back direction when rolling the reassembly material, the clotspros of the expensive laminate material can be reduced. This made it possible to improve the yield of clad plates. Furthermore, when cold rolling the clad plate obtained in this way, it is possible to omit softening annealing, pickling, and dehydrogenation annealing, and the cold rolling can be kept within a range where work hardening is not significant. This has made it possible to perform severe processing such as close bending even if final annealing is omitted. By sealing the laminate between the base material and the covering material, contamination of the surfaces to be joined is prevented and joining performance is improved. Now I can protect myself. Although the method of the present invention has been described as an example of a titanium clad steel plate which is extremely difficult to manufacture by rolling, it can also be applied to other clad materials which are difficult to manufacture.

[Brief explanation of the drawing]

1 to 3 show examples of material assembly structures when carrying out the present invention, in which FIG. 1 is a sectional view of a sandwich-like assembly used for initial rolling, and FIGS. They are a longitudinal sectional view and a transverse sectional view, respectively, of the reassembled body used for the second rolling. 1, 7... Base material, 2, 6... Laminated material, 3, 5...
... Covering material, 8 ... Fillet welded part, 9, 10 ... Nozzle, 11 ... Separation planned surface, 12 ... Surrounding welded part, 13, 13', 13'' ... Sand German cladding material, 14 ... ...Welded parts of sand germanchiklad materials, 15, 15'... Covering material, 17... Welded parts of covering material and covering material.

Claims (1)

[Claims] 1. Insert two pieces of mating material between two base materials, and
The peripheries of the two base metals are welded to form a sandwich-like assembly, the assembly is heated and rolled to join the base metal and the cladding material, and the thus obtained cladding plates are overlaid to form a sandwich-like assembly that is approximately connected to the base material. A thin-walled clad plate characterized by covering with a covering material made of the same material and fixing them to obtain a reassembled body, heat rolling the reassembled body, and then cutting and peeling the periphery of the obtained reassembled rolled material. manufacturing method. 2 The clad plate used for the reassembly maintains the original sandwich structure in which two sheets of cladding material are inserted between two base materials, and the direction of the joining position of the base materials is set at the time of rolling the reassembly. The method according to claim 1, wherein the method is performed in the front-back direction. 3 The final pass of rolling is completed at a temperature equal to or higher than the recrystallization temperature of the base material and the laminate material, and the periphery of the reassembled rolled material is cut and peeled, and then the plate thickness and shape are adjusted by cold rolling. The method according to scope 1 or 2.