JPS63238987A - Manufacture of clad steel plate having uniform cladding material thickness - Google Patents

Abstract

PURPOSE:To reduce the ununiformity of thickness and a camber of cladding material by providing dummy parts on a base metal steel original plate by an open sandwich method and arranging the original plate having the higher high-temperature deformation resistivity of the base metal steel original plate and a cladding material original plate at the lower side to perform the hot rolling. CONSTITUTION:The cladding material 1 is superposed on the base metal steel original plate 2 having the size longer than the cladding material by the prescribed quantity and the periphery is subjected to the shielded welding 3 and the dummy parts 4 projecting from respective edge of the cladding material original plate 1 are provided on the front and rear edges in the rolling direction of the base metal steel original plate 2. Next, in the case the high- temperature deformation resistance of the cladding material original plate 1 is higher than that of the base metal steel original plate 2, for instance, when the hot rolling is performed, a clad part 8 is made in a downward camber state with the rolling reduction which state continuous till the dummy part 4 comes into contact with a stopper guide 6 or a roller table 7. When the contact is carried out, then, a reaction is received and afterward, the camber is controlled and rolled down. As a result, the sound clad steel plate without the ununiform thickness of the cladding material at the front and rear edges due to the downward camber at the time of rolling can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a rad steel plate having a uniform thickness by an open sandwich rolling method.

Conventional technology Clad steel sheets, which are made by bonding other alloy steels or nonferrous alloys to the surface of steel materials such as carbon steel, low carbon steel, and high alloy steel, have high mechanical strength and corrosion resistance by taking advantage of the characteristics of each material. It is a metal material that has a combination of properties such as heat resistance, abrasion resistance, and crack resistance, and is used in oil plants,
It is used in a wide range of fields such as seawater desalination equipment and pressure vessels. One of the methods for manufacturing such clad steel sheets is the open sandwich rolling joining method, which is attracting attention because the joining operation is easy.

Conventionally, when producing a clad steel plate by such an open sandwich rolling method, the composite to be rolled is made by overlapping a laminate original plate l and a base steel original plate 2 of equal width and length as shown in FIG. 1 (1). , with shield welding 3 around the periphery, or a base steel original plate 2 whose width and length are larger than the laminate original plate 1 to the extent that shield welding of fillets is possible, as shown in Fig. 1 (II). The material used was one in which the original sheets of laminated material were overlapped and the surrounding area was shielded by fillet welding. In hot rolling of such a composite, since the high temperature deformation resistance of the laminate material and the base material steel are different, the rolling is vertically asymmetrical, and warpage occurs toward the material having greater high temperature deformation resistance. Therefore, if rolling is performed with the material having higher high-temperature deformation resistance facing upward, a large warp will occur, making it impossible to perform the rolling smoothly and possibly stopping the rolling.

Problems to be Solved by the Invention It is known that an effective method for preventing the above-mentioned warping phenomenon during rolling is to roll the material with the material having higher high-temperature deformation resistance facing downward.

However, this method causes downward warpage.

Such downward warping can be reduced by the reaction force of the roller table, but a large downward warpage occurs in the area up to the point where the tip comes into contact with the roller table during rolling, which poses the following technical problems, and it is difficult to achieve uniform rolling. It was not possible to produce a clad steel plate having a laminated material thickness with a high yield.

(a) Due to the difference in high temperature deformation resistance between the base steel and the laminate, the thickness of the gold mine material becomes non-uniform over a range of 300 to 2000 mm from the front and rear ends of the laminate after rolling.

(b) When the lower limit tolerance of the laminate material thickness and the lower limit tolerance of the base material w4 thickness are required, the finished plate thickness is determined in advance to ensure that the thickness at the front and rear ends of the laminate material or base material steel is greater than the lower limit tolerance. Must be rolled large.

(c) In addition to the lower limit tolerance of the laminate thickness and the lower limit tolerance of the base material adjustment thickness, if the upper limit tolerance of the total thickness is required, the area of the leading and trailing edges that does not satisfy the gold mine thickness tolerance or the base material adjustment thickness tolerance is It has to be cut down.

Means for solving the problem, that is, the present invention is to provide a base steel base plate and a laminate material to at least one of the front and rear ends and both side surfaces of the base steel base plate in the rolling direction when manufacturing a clad steel plate by the oven sandwich rolling method. A uniform method characterized by providing a dummy portion protruding beyond the welding allowance of the thick plate, and hot rolling with the material with greater high-temperature deformation resistance of the base steel original plate and the laminated thick plate on the lower side. The present invention provides a method for manufacturing a clad steel plate having a laminated material thickness of the same thickness.

The present invention will be explained in detail below.

FIG. 2 is a cross-sectional view in the rolling direction of a composite used in the method of manufacturing a clad steel plate by the oven sandwich rolling method of the present invention.

In order to produce the composite, the laminated material l and the base steel original plate 2, which is longer than the laminated material by a predetermined length, are overlapped, and the periphery thereof is shield welded 3, so that the rolling direction of the base steel original plate 2 is adjusted. A dummy portion 4 is provided at the front and rear end portions, protruding from each end of the laminated material thick plate l. The method for forming the dummy portion is as follows: The length dimension of the base steel original plate 2 is adjusted to the thickness of the laminated thick plate I.
In addition to the method of making the dummy part 4 larger than that of
Dummy parts 4 may be provided at the front and rear ends of the base steel original plate in the rolling direction by welding or the like.

As another method, the dummy parts 4 may be provided on both side surfaces of the base steel original plate 2, or the dummy parts may be provided on both the front and rear ends in the rolling direction and both side faces of the base steel original plate 2. .

Further, the appropriate length of the dummy portion varies depending on the cladding ratio, heating conditions, rolling conditions, and the structure of the rolling mill.

Examples of the laminated thick plate used in the method for producing a clad steel plate of the present invention include stainless steel, Ni%Ni-based alloy, Cu, and Cu alloy. On the other hand, carbon steel, low alloy steel, high alloy steel, etc. are used as the base steel original plate.

Next, the composite rolling method will be explained.

FIG. 3 is a schematic cross-sectional view showing how the composite shown in FIG. 2 is hot-rolled to produce a clad steel plate by the method of the present invention. A case where the size is larger than the steel original plate 2 is shown. The cladding part 8 of the composite is bent downward as it is rolled down, and the dummy part 4 is connected to the stripper guide 6.
Alternatively, this state continues until it contacts the roller table 7. When the dummy part 4 comes into contact with the stripper guide 6 or the roller table 7, it receives a reaction force there and is thereafter rolled down in a manner in which warping is suppressed. As a result, it is possible to obtain a sound rad steel plate in which there is no non-uniformity in the thickness of the leading and trailing parts due to downward warping during rolling.

In addition, when rolling a composite with dummy parts on both sides, the gummy part made of a single layer of base steel works to suppress the warping that occurs in the cladding part, and as a result, the warping during rolling is reduced. . If dummy parts are further added to the leading and trailing ends in the rolling direction of the bending composite, the effect of suppressing warpage will be significantly increased, and a rad steel plate with a uniform thickness can be manufactured at an even higher yield.

EXAMPLES Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

The manufacturing conditions and results are summarized in Table 1.

Example 1 As shown in Table 1, a 5US304 original plate was used as the laminate material original plate, an SS41 slab was used as the base steel original plate, and the first
As shown in the table, some gummies (
A welding margin (each 100 mm) was provided at the leading and trailing ends in the rolling direction, and the laminate material original plate and base material steel original plate were restrained by a band-shaped electrode overlay welding method with a hoop width of 75 openings. An oven sandwich type composite was produced and further hot rolled under the conditions shown in Table 1.

As a result of measuring the obtained clad steel plate, the degree of thickening of the laminate at the front and rear ends of the clad steel plate was 1.18.
In addition, the degree of downward warping of the leading and trailing ends of the clad plate during rolling was small and good.

Comparative Example 1 As shown in Fig. 1 (II), the mother of the composite had welding allowances (each 10
A cladding AT was produced under the same conditions as in Example 1 except that only 10Os was provided.

The degree of thickening of the laminate material at the leading and trailing ends of the obtained clad conditioned plate was 1.50, and the degree of downward warping of the leading and trailing ends of the clad steel plate during rolling was also large.

Example 2 As shown in Table 1, everything was the same as Example 1 except that dummy parts (250 mm each) were provided at the front and rear ends of the base steel original plate in the rolling direction, and welding allowances (100 mm each) were provided on both side surfaces. A clad U plate was produced under the same conditions.

The degree of thickening of the cladding material at the leading and trailing ends of the obtained clad steel plate was as small as 1.14, and the degree of downward warping of the leading and trailing ends of the clad steel plate during rolling was also small and good.

Effects of the Invention - As described above, according to the present invention, non-uniformity in the thickness of the laminate material that occurs at the leading and trailing ends in the rolling direction is avoided when manufacturing a clad steel plate consisting of a base steel and a laminate material each having different high-temperature deformation resistance. and reduce warping.

With this, it has become possible to manufacture clad steel plates having a laminate with a uniform thickness that satisfies strict plate thickness tolerances. Furthermore, as an additional effect of the present invention, the dummy portions at the leading and trailing ends or both side surfaces suppress warping in the width direction and length direction that occur during the air cooling process after rolling. It has become possible to significantly reduce the amount of effort.

[Brief explanation of drawings]

Figures 1 (1) and (■) are cross-sectional views perpendicular to the rolling direction of a composite used in the conventional oven sandwich rolling method for producing clad steel plates; - Figure 2 is an oven sandwich of the present invention; FIG. 3 is a cross-sectional view in the rolling direction of a composite used in a method for manufacturing a clad steel plate by a rolling method. FIG. The main symbols in the drawings are as follows. l... Laminated material original plate, 2... Base material steel original plate, 3.
...Shield welding (part), 4...Dummy part,
5... Work roll. Patent Applicant: Kobe Steel Oriyoshi Co., Ltd. Patent Attorney: 2 people (including the above) Figure 1 (I) Figure 1 (N) Figure 2

Claims (1)

[Claims] (1) When manufacturing a clad steel plate by the open sandwich rolling method, at least one of the leading and trailing ends and both side surfaces of the base steel base plate of the composite in the rolling direction protrudes beyond the welding allowance between the base steel base plate and the clad base steel base plate. A clad steel plate having a uniform laminate thickness, characterized in that a dummy portion is provided, and the material having a higher high-temperature deformation resistance of the base steel original plate and the cladding material original plate is placed on the lower side and hot rolled. Production method.