JPH0366486A - Manufacture of aluminum clad steel plate by open sandwich method - Google Patents

Abstract

PURPOSE:To suppress chattering wave and to improve productivity by forming an Al thermally sprayed coat at the top end in the lengthwise direction on the rear of a base material, forming an Al thermally sprayed coat on the surface except the top end part in the lengthwise direction on the surface of the base material, laminating, heating and rolling clad materials on both sides of the base material. CONSTITUTION:An Al plate 4 is set on the surface of a steel 3 except its top ends and an Al plate 4 is set at the top end of the lower surface (rear) of the steel 3, too. Consequently, since the amount of deformation of the Al in a rolling time is remarkably larger than that of the steel, an upward bending moment is generated at the top end part. Further, bending stress is given to a steel plate, the top end plate takes an upward camber, collision to the table roller is prevented and carriage is performed. Thus, generation of chattering wave is prevented and productivity is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is directed to an open sandwich method (two parts of laminated material and base material).
The present invention relates to a method for manufacturing aluminum clad steel sheets by a rolling bonding method (method using a layered composite).

(Prior art and problems to be solved) So-called aluminum-clad steel plates, which are steel plates clad with aluminum plates, are being used in various fields as metal materials with complex functions such as mechanical properties, corrosion resistance, and electrical properties. , a conventional explosive crimping method that utilizes the explosive energy of explosives to bond.

Alternatively, they are manufactured by a rolling joining method, etc., in which pressure joining is performed by rolling.

However, the explosive crimping method has a high manufacturing cost and is not suitable for manufacturing inexpensive aluminum clad steel sheets. On the other hand, the rolling joining method is suitable for producing inexpensive aluminum-clad steel sheets.

The rolling joining method involves heating the laminate material and base material by overlapping them.
There are two methods: hot rolling and cold rolling without heating.

Generally, when producing an aluminum clad steel plate with a thickness of 8@■ or more by a rolling bonding method, a hot rolling method is employed, but in this case, it is necessary to prevent oxidation. Furthermore, when rolling a two-layer structure of laminate material (aluminum) and base material (steel) using the open sandwich method, the amount of aluminum deformation during rolling is significantly larger than that caused by rust, so as shown in Figure 1, in area A downward bending moment is generated and bending stress is applied to the steel plate. When aluminum-clad steel sheets are rolled, they are usually heated to about 500° C., so this bending stress is greater than the yield stress of the steel sheet, and at this stage the steel sheet undergoes downward warping deformation. Since the tip is curved downward on the exit side of the rolling mill, as rolling progresses toward the rear end, the tip collides with the table rollers on the exit side of the rolling mill one after another, causing an upward bending moment. This causes bending stress to be applied to the steel plate, causing upward warpage and the formation of small waves along the table roller pitch over the entire length of the steel plate, so-called chatter waves. At this point, due to the large downward curvature, further conveyance by table rollers becomes impossible, leading to problems such as extremely poor productivity.

The present invention has been made in order to solve the problems of the prior art described above, and is a method that facilitates the rolling of a two-layer structure of aluminum-steel, and in particular allows the production of aluminum-clad steel plates with a thickness of 8+U+ or more at low cost. The purpose is to provide the following.

(Means for Solving the Problem) In order to achieve the above-mentioned object, the present inventors searched for a protective film that has a high oxidation prevention effect on steel sheets and does not form a harmful embrittlement layer, and in addition, As a result of intensive research to find manufacturing conditions that suppress the occurrence of chatter waves, which are difficult to correct, and enable conveyance by table rollers in the rolling of a two-layer structure, the method of the present invention was discovered.

That is, the method for manufacturing an aluminum clad steel sheet according to the present invention uses aluminum or an aluminum alloy as a laminated material,
When manufacturing aluminum clad steel sheets using carbon steel, low alloy steel, etc. as a base material by the open sand inch method, an aluminum spray coating is formed on the longitudinal tip of the back surface of the base material, and at the same time, an aluminum spray coating is formed on the base material surface other than the longitudinal tip. It is characterized by forming an aluminum sprayed coating on the surface, laminating a cleaned laminate on the front and back surfaces of the base material on which the sprayed coating is formed, fixing the laminate and the base material, and then heating and rolling. It is something to do.

In addition, another aspect of the present invention provides that when manufacturing an aluminum clad steel plate using aluminum or an aluminum alloy as a laminated material and a base material such as carbon steel or low-alloy steel by an open sand inch method, the tip of the base material in the longitudinal direction is After bending upward by bending, an aluminum sprayed coating is formed on the surface of the base material other than the tip, and a cleaned laminate is laminated on the surface of the base material on which the sprayed coating is formed. It is characterized by heating and rolling after fixing the material and the base material.

The present invention will be explained in more detail below.

(Function) The greatest feature of the present invention is that by curving the tip of the plate upward in the longitudinal direction, it prevents the tip from colliding with the table roller, suppresses chatter waves, and enables conveyance by the table roller. At the point.

Specifically, the first method is usually aluminum
In rolling steel with a two-layer structure, aluminum or aluminum alloy (hereinafter simply referred to as "r-aluminum") is applied to the upper surface of the steel.
However, in the present invention, as shown in Fig. 2, in addition to setting the aluminum plate with the tip left on the surface of the steel, an aluminum plate is also set on the tip of the lower (back) surface of the steel. It is. According to this method, the amount of deformation of aluminum during rolling is significantly larger than that of steel, so an upward bending moment is generated at the tip, applying bending stress to the steel plate, and the tip becomes warped. , it is possible to prevent collisions with table rollers and enable conveyance.

In addition, as another means, as shown in Figure 3,
The aluminum plate is set offset from the tip of the base steel, and the tip of the base steel where the aluminum plate is not set on the upper surface of the steel is bent using a press or the like so that it is warped upward. As a result, even if the downward bending moment acts during rolling and causes the tip to return downward, the tip is curved upward, so as with the first method, it prevents collision with the table roller and suppresses the generation of chatter waves. Moreover, it enables conveyance by table rollers.

Furthermore, in any of the above methods, aluminum is thermally sprayed to form a thermal spray coating on the base metal side surface to be joined in order to prevent oxidation during heating.

In that case, there are considerable pores in the sprayed layer, so
In order to effectively isolate the steel plate surface from the atmosphere, it is preferable that the thickness of the sprayed layer be 50 μm or more. Note that the means for forming the aluminum sprayed coating is not limited.

Of course, the material and plate thickness of aluminum and steel in the present invention.

Fixing means, heating, rolling conditions, etc. are not particularly limited.

Next, examples of the present invention will be shown.

(Example) Steel plates and aluminum plates with the details shown below were prepared, and a composite was assembled, heated, and rolled under the conditions shown in Table 1.
Manufactured aluminum clad steel plates.

Steel plate: (Material) S41 (Size) 25t x 340w x 3000Q
Aluminum plate = (Material) Industrial aluminum plate (Size) 8
t X340w X2000128t X340wX3
00u (for fixing the back surface) The obtained material was examined for the amount of warpage, presence or absence of chatter waves, and shear strength. The results are also listed in Table 1.

Regarding the amount of warpage, the obtained material was placed on a surface plate, the gap between the surface plate and the steel plate was measured, and the value was expressed as the maximum value.

As is clear from Table 1, no chatter waves were observed in any of the invention examples N11l and M2.

In addition, since the amount of warpage was small, it was possible to transport the table roller sufficiently.In contrast, a comparative example of a normal aluminum-steel two-layer composite assembled without any special measures at the tip & 3 Although the shear strength was about the same, chatter waves occurred and the amount of one warp was extremely large, making it impossible to transport using table rollers.

[Margin 1 (Effects of the Invention) As detailed above, according to the present invention, since a means for warping the tip of the composite upward during rolling is taken,
The generation of chatter waves can be suppressed, and warping during rolling is slight, which not only makes handling after rolling easier, but also significantly reduces the straightening time required to ensure product flatness. Improved yield, productivity, etc.
Has excellent effects. It is particularly suitable for manufacturing aluminum clad steel plates with a thickness of 8 mm or more.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the mechanism by which downward warpage occurs during rolling of an aluminum-steel two-layer structure. FIG. 2 is a sectional view illustrating the structure of the composite according to the present invention. FIG. 3 is a sectional view illustrating another structure of the composite according to the present invention. 1... Upper roll, 2... Lower roll, 3... Steel, 4
···an alminium board.

Claims (2)

[Claims] (1) When manufacturing an aluminum clad steel plate using aluminum or aluminum alloy as a laminating material and carbon steel, low alloy steel, etc. as a base material by the open sandwich method, an aluminum spray coating is formed on the longitudinal tip of the back surface of the base material. At the same time, an aluminum sprayed coating is formed on the surface of the base material other than the tip in the longitudinal direction, and a cleaned cladding material is laminated on the front and back surfaces of the base material on which the sprayed coating is formed, and the cladding material and the base material are fixed. A method for producing an aluminum clad steel sheet, which comprises heating and rolling the aluminum clad steel sheet. (2) When manufacturing an aluminum clad steel plate using aluminum or aluminum alloy as a laminate and a base material such as carbon steel or low-alloy steel by the open sandwich method, by bending the longitudinal tip of the base material. After bending upward, an aluminum sprayed coating is formed on the surface of the base material other than the tip, and a cleaned laminate is laminated on the surface of the base material on which the sprayed coating is formed, and the laminate and base material are fixed. A method for producing an aluminum clad steel sheet, which comprises heating and rolling the aluminum clad steel sheet.