JPS60244490A - Production of clad steel plate - 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 [Technical Field of the Invention] The present invention relates to a method for manufacturing clad steel sheets.

[Prior art and its problems]

Conventionally, the following method has been used as one of the methods for manufacturing a clad steel plate in which a laminate plate is laminated on a base plate.

■ Clean the mating surfaces of the base material plate and the laminated material plate, apply N1 plating to at least one of the cleaned surfaces, overlap the base material plate and the laminated material plate, and weld the surroundings. The assembled slabs, which are assembled by the so-called open sand inch method, are heated to a predetermined temperature and then rolled to bond the base material plate and the laminated material plate.

(2) After cleaning the mating surfaces of the base material plate and the mating material plate, N1 foil is sandwiched between them, and a slab is assembled and rolled in the same manner as described above.

In the above-mentioned manufacturing methods (1) and (2), an N1 plating coating is formed/removed between the base material plate and the laminated material plate, and N1 foil is inserted.d-1 The assembled slab is rolled. In order to prevent the carbon in the base material plate from diffusing into the laminated material plate, thereby preventing a decrease in the corrosion resistance of the laminated material plate and a decrease in adhesive strength between the base material plate and the laminated material plate. It is.

The above-mentioned method (2) not only takes time and money to apply plating, but also requires plating with a thickness of 30 to 40 μm or more.
Therefore, there is a problem that the above-mentioned diffusion of carbon cannot be sufficiently prevented.

On the other hand, in the method (■) mentioned above, the N1 foil is expensive, and
Depending on the size of the slab, too much N1 foil is wasted, and the maximum thickness of available N1 foil is 100 to 120 μm.
m, so there is the problem that carbon diffusion cannot be sufficiently prevented, similar to the method (2).

[Purpose of the invention]

Therefore, an object of the present invention is to change the thickness of the metal N1 interposed between the base material plate and the laminated material plate from the base material plate to the laminated material plate, depending on the composition of the base material plate, the rolling conditions of the slab, etc. To provide a method for producing a clad steel sheet, which can be easily adjusted according to the amount of carbon diffused into the clad steel sheet, and thereby reduce the proportion of carbon diffused from the base material sheet into the laminated material sheet. It is in.

[Summary of the invention]

Forming a coating of metal N+ on the mating surface of at least one of the base material plate and the laminated material plate by a thermal spraying method, stacking the base material plate and the said laminated material plate with each other to assemble a -C slab, and rolling the slab. It is characterized by manufacturing clad steel sheets using the same method.

[Structure of the invention]

As described above, the feature of this invention is that a coating of metal N1 is formed on the mating surface of at least one of the base material plate and the mating material plate by a thermal spraying method. The surfaces are cleaned by pickling or other means before thermal spraying, and then the thus cleaned mating surfaces are subjected to a blasting treatment such as shot blasting or sandblasting to give the mating surfaces a rough surface. It is desirable to improve the adhesion with the metal N1 coating.

According to this invention, the thickness of the metal Ni coating can be freely adjusted by changing the thermal spraying conditions of the metal N1, such as changing the thermal spraying speed (solvent area/spraying time) or changing the number of thermal sprayings.

Therefore, even if the composition (mainly carbon content) of the base plate changes, the amount of carbon diffusion into the laminated plate can be suppressed within the desired range. Even if the rolling reduction ratios of the slabs differ significantly, the thickness of the metal N1 coating in the rolled clad steel sheet can be maintained constant.

[Embodiments of the invention]

Next, embodiments of the invention will be described with reference to the drawings.

The mating surfaces of the base material plate and the laminated material plate having the composition shown in Table 1 were cleaned, and the mating surfaces of the laminated material plate were subjected to shot blasting treatment. Next, a metal N1 coating with a thickness of 20 μm was formed on the mating surfaces of the laminated material plates thus roughened by thermal spraying under the conditions shown in Table 2.

As shown in Table 2, the variation in the thickness of the metal N1 coating is significantly smaller than when using N1 foil.

This is because when using N1 foil, multiple sheets of N1 foil are laid out between the base material board and the laminated # board with their edges slightly wrapped, so the thickness of the wrapped part is naturally greater than that of other parts. This is because it is thicker.

The base material plate and the laminated material plate obtained in this way were
Assemble as shown in the diagram. That is, the base material plate 1 and the laminated material plate 2 on which the metal N1 coating E, 3 is formed on the mating surfaces are stacked on each other, and the two plates thus stacked are made of aluminum.
l! The base material plates 1 were stacked vertically and symmetrically with each other facing outward via a release agent 4 made of 203, and a dummy material plate 4 was welded around the entire circumference to assemble a slab.

Next, the slab assembled in this way was heated to 1250°C and hot-rolled to a thickness of 12 ms (base material plate thickness: 10 sheets, laminated material sheet thickness: 2 mm), width of 3100 mA, Two clad steel plates with a length of 13,500 m were obtained.

The edges of the clad steel plate thus obtained were trimmed to give a thickness of 12 mm, a width of 3000 ms, and a length of 1250 ms.
Two clad steel plates with dimensions of 0 m were obtained as final products. Then, a test piece was cut from one of the products and the carbon content in the laminated material board 2 was examined.

This result is shown in the case where the mating surface of the laminated material plate 2 is plated with 20 μm of Ni (conventional method A), and when the old foil of 100 μm is sandwiched between the base material plate 1 and the laminated material plate 2. The results are shown in FIG. 2 together with the results of (conventional method B). Note that other conditions in these conventional methods are the same as in the above-mentioned embodiments.

As is clear from FIG. 2, according to the method of this invention,
The amount of carbon diffused from the base material plate 1 into the laminated material plate 2 can be reduced compared to the conventional method.

〔Effect of the invention〕

As explained above, according to the present invention, the thickness of the metal N1 interposed between the base material plate and the laminated material plate is determined depending on the composition of the base material plate, the pressure 1fi' of the assembled slab, conditions, etc. It can be easily adjusted according to the changing amount of carbon diffusing from the base material plate into the laminated material plate, so it is possible to reduce the corrosion resistance of the laminated material plate due to diffused carbon and the adhesion between the base material plate and the laminated material plate. This brings about the extremely useful effect of preventing a decrease in strength.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the assembled state of the slab used in the embodiment of this invention, and Fig. 2 shows the distance from the bonding surface between the base material plate and the laminated material plate, and the carbon content in the laminated material plate. It is a graph showing the relationship with quantity. In the drawings, 1...Base material plate 2...Laminated material plate 3...Metal Ni coating 4...Dummy material plate Applicant: Natsuo Shioya (and 2 other people), agent of Nippon Doppan Co., Ltd. Figure 1 Figure 2 0 100 200 300

Claims (1)

[Claims] Forming a coating of metal N1 to a desired thickness on the mating surface of at least one of the base material plate and the laminated material plate by a bath irradiation method, and assembling a slab by overlapping the base material plate and the said laminated material plate with each other, A method for producing a clad steel plate, comprising rolling the slab to produce a clad steel plate.