JPH0327884A - Manufacture of aluminum clad steel plate - Google Patents

Abstract

PURPOSE:To improve the metallic joining strength of an aluminum plate of a clad material and a steel plate of a base material by providing the ruggedness of a specific shape on the surface of the steel plate of the base material, and also, forming film of thermal spray on the surface of the base material. CONSTITUTION:An aluminum clad steel plate whose clad materials is formed by aluminum or an aluminum alloy and base material is a steel plate is manufactured by a rolling joining method. In this case, the clad material is heated to a temperature of 400 deg.C - <= melting temperature, and as for a base material, on the surface to be a joint surface, ruggedness of 100-500mu depth and 100-1000mu width and length is provided, and film of thermal spray of aluminum is formed thereon. Subsequently, after heating to a temperature of 100-550 deg.C, the clad material is superposed onto the film of aluminum thermal spray of the base material in front of a rolling mill, and thereafter, rolling is executed so that a draft of the clad material becomes >=10% in at least one pass. In such a way, a clad steel plate whose joining strength is high, and accordingly, whose shearing strength is also high can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing an aluminum clad steel plate,
More specifically, it is a method of manufacturing an aluminum clad steel plate by a rolling joining method.

[Prior Art 1 A so-called aluminum clad steel plate, which is made by cladding an aluminum plate or an aluminum alloy plate (hereinafter sometimes simply referred to as an aluminum plate) with steel, has mechanical properties,
It has been used for various purposes as a metal material with multiple functions such as corrosion resistance and electrical properties.

This aluminum clad steel temporary is produced by the explosive crimping method, which utilizes the explosive energy of explosives to bond the laminated aluminum plate to the base steel plate, or by rolling the laminated aluminum plate and the base steel plate by overlapping them. It is manufactured by a rolling bonding method that uses pressure bonding.

However, since the explosive crimping method uses explosives, it requires a place that is not affected by the explosion noise, and the explosives must be handled with great care, which increases manufacturing costs and makes it difficult to manufacture inexpensive clad steel sheets. It is inappropriate for Further, the rolling joining method includes a method in which an aluminum plate as a laminated material and a steel plate as a base material are overlapped and then hot rolled by heating, and a method in which cold rolling is performed without heating.

Generally, when manufacturing a clad steel plate having a thickness of 8 mm or more by a rolling joining method, a hot rolling method is adopted.

However, when hot rolling is performed by heating the aluminum plate as the laminated material and the steel plate as the base material to a predetermined temperature,
The shear strength is about 1 kgf/mm'', and there is a problem that the bonding strength is extremely low as a clad steel plate.

[Problems to be Solved by the Invention] The present invention solves the problem of low shear strength when manufacturing the conventional clad steel plate described above, that is, a clad steel plate made of a composite material of aluminum or aluminum alloy plates and a base material of a steel plate. In view of this problem, the present inventor conducted intensive research,
As a result of repeated studies, we found that in order to improve shear strength, we should physically create wavy or rectangular irregularities on the surface of the base steel sheet, and then form an aluminum spray coating on the surface of this base material to improve the bonding surface. We have developed a method for manufacturing aluminum clad steel plates that can prevent the oxidation of aluminum plates and increase the strength of the metal bond between the laminated aluminum plate and the base steel plate, that is, increase the shear strength.

[Means for Solving the Problems] The method for manufacturing an aluminum clad steel sheet according to the present invention is characterized by: using aluminum or an aluminum alloy as a laminating material;
When manufacturing aluminum clad steel plates using a steel plate as a base material by the rolling joining method, the laminated material is heated to a temperature of 400°C to less than the melting temperature, and the base material serves as the joint surface and is bonded to a depth of 1.
00 to 500μ, width and length of 100 to 1000μ are provided, and a sprayed aluminum coating is formed on top of the unevenness.
■After heating to a temperature of 00 to 550°C, layer the laminated material on the aluminum spray coating of the base material in front of the rolling mill, and then roll the laminated material so that the rolling reduction ratio of the laminated material is at least 10% for at least 1 pass. The purpose is to perform rolling.

The method for manufacturing an aluminum clad steel sheet according to the present invention will be described in detail below.

When rolling an aluminum plate overlaid with a steel plate, the deformation resistance of the aluminum is compared to that of the steel plate.
It is an aluminum plate that deforms because it is quite small.
Steel plates hardly deform.

Therefore, if unevenness is provided on the steel plate before rolling, the joint surface will have an uneven shape even after rolling, and the shear strength will be significantly increased. However, the uneven shape provided on the joint surface of the steel plate may be wavy or rectangular, but the depth, width,
You need to control the length.

That is, if the depth and width are less than 100 μm, the effect of increasing shear strength will be reduced, and this is because the strong base material will be less effective in resisting shear stress.

Further, even if the depth exceeds 500 μm, the effect of increasing the shear strength is saturated, and processing into an uneven shape becomes complicated and costs increase.

Furthermore, when the width and length exceed 1000μ, the variation in shear strength increases.

The effect of the uneven shape provided on the steel plate explained above is effective only when the aluminum thermal spray coating is formed on the joint surface of the steel plate with the unevenness, and if the thermal spray coating is not provided, the bond between the steel plate and the aluminum plate is Since the strength is extremely low,
The shear strength is as low as about 3 kgf/am'' at most.

When aluminum is thermally sprayed onto the joint surface of a steel plate that has irregularities, there are considerable pores in the sprayed layer, so in order to effectively isolate the steel plate surface from the atmosphere, the thickness of the sprayed layer must be adjusted. It needs to be 50 μm or more. Note that any method may be used to form this aluminum spray coating.

The heating temperature of the aluminum plate bonding material needs to be 400° C. or higher in order for the aluminum to plastically deform and join, but it must be lower than the temperature at which the aluminum melts.

If the heating temperature of the steel plate is less than IOO°C, heat absorption from the stacked aluminum plates will increase, and the aluminum plate will not be plastically deformed, and if the temperature exceeds 550°C, the yield strength will be extremely reduced.

Next, the aluminum plate as the laminated material and the steel plate as the base material are overlapped and rolled, but the rolling reduction ratio of the laminated aluminum plate needs to be 10% or more for at least 61 passes. Utilizing the plastic flow of the aluminum plate to completely collapse the thin oxide film that forms on the joint surface of the aluminum plate to the base steel plate, this is an important condition that is essential for immediately crimping. Yes, the reduction rate is l
If it is less than 0%, the bonding strength will be extremely reduced.

Note that as the laminating material, pure aluminum or an aluminum alloy of an appropriate composition can be used depending on the required composite function. Furthermore, various types of steel such as carbon steel and low alloy steel can be used as the base material steel plate.

[Example] An example of the method for manufacturing an aluminum clad steel plate according to the present invention will be described.

Example After heating the steel plate as the base material and the aluminum plate as the laminated material under the conditions shown in Table 1, the aluminum plates as the laminated material were stacked on top of each other in front of the rolling mill so that the base material steel plate was on the lower side, and rolled. I did this.

Base material steel plate Steel plate: SS41 Dimensions (+nm): 25tX340wX30001 Laminated material aluminum plate Aluminum plate: Industrial pure aluminum Dimensions (n+
+n) = 8tx340wx25QOl In Table I, No. l-No. l 7, No. 1 9
~No. No. 23 has an aluminum spray coating, and has an N
o. 18 does not have an aluminum spray coating.

No. 1 manufactured by the method for manufacturing an aluminum clad steel sheet according to the present invention. l-No. 4.No. 7~N
o. I O, No. 1 3～No, 1 5, No
．． 1 9 ~No. 20 has a shear strength of 7 kgf/m
m' or more.

However, Comparative Examples No. 5 and No. 6, No. 11,N
o. l2, No. 16, No. l 7 has a shear strength of 4
kgf/IIlm” or less.

Also, No. It can be seen from the results of 18 that aluminum spraying is necessary.

No. 211 No. 22, No. 2 and 3 indicate the influence of hot rolling conditions, and unless the conditions of the method for producing an aluminum clad steel sheet according to the present invention are satisfied, sufficient shear strength cannot be obtained.

In addition, No. 12, No. 1 7 is length and width 1
200 μm, and the shear strength tends to vary.

In other words, the two types of shear strength, high and low, are:
[Effect of the Invention] As explained above, since the method for producing an aluminum clad steel sheet according to the present invention has the above configuration, the aluminum plate or aluminum alloy plate of the laminated material and the mother plate are It has the excellent effect of high bonding strength with the steel plate of the material and therefore high shear strength.

Claims (1)

[Claims] Aluminum or aluminum alloy is used as a laminated material,
When manufacturing aluminum clad steel plates using a steel plate as a base material by the rolling joining method, the laminating material is heated to a temperature of 400°C to below the melting temperature, and the base material is bonded to a depth of 1°C on the surface that will be the joint surface.
00 to 500μ, width and length of 100 to 1000μ are provided, and a thermal sprayed aluminum coating is formed on it.
After heating to a temperature of 100 to 550°C, a laminated material is layered on the aluminum sprayed coating of the base material in front of a rolling mill, and then rolled so that the rolling reduction of the laminated material is 10% or more for at least one pass. A method for producing an aluminum clad steel sheet.