JPH04270080A - Production of aluminum clad steel sheet excellent in joining property - Google Patents

Abstract

PURPOSE:To produce an aluminum clad steel sheet in which shearing strength is stabilized at high value and superior joining property is provided. CONSTITUTION:At the time of producing an aluminum clad steel sheet, in which aluminum or aluminum alloy is used as a cladding material 2 and a steel sheet is used as a base material 1, by a rolling joining method, a composite where one or >=2 kinds among aluminum, aluminum alloy, nickel, and nickel alloy are interposed as an insert material 3 between the cladding material and the base material, is prepared and heated up to a temp. between 250 deg.C and a temp. lower than the melting temp. of aluminum and at least one pass is performed by means of rolling under the condition that the rolling reduction of the cladding material is regulated to 10%. At this time, it is effective in improving joining property that the periphery of the above insert material is stuck on the surface of the base material and hermetically sealed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing aluminum clad steel sheets by a rolling bonding method.

0002

[Prior Art and Problems to be Solved by the Invention] A so-called aluminum clad steel plate, which is a steel plate clad with aluminum or an aluminum alloy plate (laminated material), is a metal that has complex functions such as mechanical properties, corrosion resistance, and electrical properties. It is being used as a material in a variety of fields, and has conventionally been manufactured by the explosive crimping method, which utilizes the explosive energy of explosives to bond, or the rolling bonding method, which crimps by rolling.

[0003] However, the explosive crimping method has a high manufacturing cost and is not suitable for manufacturing aluminum clad steel sheets at low cost. On the other hand, the rolling joining method is suitable for producing inexpensive clad steel plates.

[0004] Roll joining methods include a method in which the laminate material and the base material are overlapped, heated and hot rolled, and a method in which the material is cold rolled without heating. Generally, hot rolling is used to manufacture aluminum clad steel sheets with a thickness of 8 mm or more using the rolling bonding method. In addition, small cavities remain, and the surface of the base material is oxidized, and this oxide film may remain at the bonding interface, so it was difficult to say that the bonding performance was necessarily good.

The present invention has been made to solve the problems of the prior art described above, and an object of the present invention is to provide a method for industrially producing aluminum clad steel sheets with excellent bonding properties at low cost. It is something.

[0006]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the inventors of the present invention sought to find a method capable of promoting pressure bonding between the laminated material and the base material and reducing oxidation of the surface of the base material during heating. As a result of extensive research, we created a composite in which one or more of aluminum, aluminum alloy, nickel, or nickel alloy was interposed as an insert material between the laminated material and the base material, and then hot-rolled this composite. The inventors have discovered that the remaining cavities and oxide film at the bonding interface can be reduced by this method, and the present invention has been developed based on this finding.

In other words, the method for manufacturing an aluminum clad steel sheet according to the present invention is to manufacture an aluminum clad steel sheet using aluminum or an aluminum alloy as a laminated material and a steel plate as a base material by a rolling joining method. After producing a composite in which one or more of aluminum, aluminum alloy, nickel, and nickel alloy is interposed as an insert material, this is
It is characterized by heating to 0° C. or higher and lower than the melting temperature of aluminum, and rolling under conditions such that the rolling reduction of the laminated material is 10% or higher for at least one pass. Further, the four circumferences of the insert material are pasted and sealed on the surface of the base material, which is effective in improving bonding performance.

The present invention will be explained in more detail below.

[0009]

[Operation] First, one of the features of the present invention is that an insert material made of a specific material is interposed between the laminate material and the base material.

[0010] When a composite with a two-layer structure of laminated material and base material is heated and rolled, a gap is created between the laminated material and the base material, so the surface of the base material is oxidized during heating, and the laminated material and base material are Since the cavity existing at the bonding interface is not completely crimped and some portion remains, bonding performance deteriorates.

On the other hand, when a composite in which one or more of aluminum, aluminum alloy, nickel, and nickel alloy is interposed as an insert material between the laminated material and the base material is hot rolled, the insert material becomes the laminated material. The insert material fills the gap between the insert material and the base material, reduces oxidation on the surface of the base material, and fills the void at the bonding interface, making it possible to obtain an aluminum-clad steel sheet with excellent bondability.

[0012] Next, the composite having such a structure is heated and rolled. Naturally, the heating temperature during rolling should be lower than the melting temperature of aluminum, but if the temperature is lower than 250°C, the bonding material-insert material - A large amount of rolling reduction is required for crimping the base material, which not only exceeds the capacity of the rolling mill, but also may cause cracks in the aluminum plate, which is undesirable. Therefore, the appropriate heating temperature is
The range is 250°C or higher and lower than the melting temperature of aluminum.

[0013] Further, the rolling reduction is an important condition in the present invention, and the rolling reduction of the laminated material (ie, aluminum or aluminum alloy) must be 10% or more in at least one pass. This is an indispensable element in order to utilize the plastic flow of aluminum to completely collapse the thin oxide film that has formed on the aluminum surface to be joined, and to press-bond the aluminum immediately after that. If the reduction rate is less than 10%, bondability will be extremely reduced and should be avoided.

[0014] Prior to hot rolling, it is preferable that the four circumferences of the insert material be attached to the surface of the base material and sealed. This is because it is effective in increasing the effect of reducing oxidation on the surface of the base material. This is because simply interposing the insert material between the mating material and the base material does not completely seal the surface of the base material. In order to suppress oxidation of the base material surface and improve the bondability of aluminum-clad steel sheets, it is effective to attach and seal the four circumferences of the insert material to the base material surface as shown in FIG. The means of sealing is not particularly specified.

[0015] As the aluminum plate of the laminated material, pure aluminum or aluminum alloys of various compositions or thicknesses can be used depending on the desired composite function. As for the insert material, the material and thickness can be used as appropriate depending on the type of the laminated material and the heating temperature. As the base material steel plate, one of appropriate material and thickness can be used depending on the desired composite function of the aluminum clad steel plate.

The present invention can also be applied to cases where the surface of the base material is thermally sprayed or plated, and great effects can be obtained.

Next, examples of the present invention will be shown.

[0018]

[Example] A base material, an insert material, and a laminated material having the details shown below were prepared, a composite was assembled, and then heated and rolled to produce an aluminum clad steel plate.

[0019] Details: Material of laminating material: Industrial pure aluminum plate (A1050P) Size of laminating material: 5t x 250w x 700L
mm Insert material material: Aluminum foil, nickel foil Insert material size: 50μt x 270w x 10
00Lmm Base material material: SS41 Base material size: 20t x 300w x 1000Lm
m

Regarding the obtained aluminum clad steel plate,
UT bondability (by ultrasonic testing) and shear strength were investigated. The result

[Table 1] Shown below.

In Table 1, No. 1~No. Sample No. 5 is an example of the present invention, and has good UT bondability and shear strength. In particular, No. 3 and no. No. 5 is a material in which the four circumferences of the insert material are pasted and sealed on the surface of the base material with heat-resistant tape, and the shear strength is stable at a high level of 6.0 to 7.0 kgf/mm2.

On the other hand, Comparative Example No. No. 6 had a two-layer structure of laminated material and base material, and some non-bonding occurred. Also,
The shear strength varies widely and its value is low. Comparative example N
o. In No. 7, the heating temperature was less than 250° C., and the entire surface was not bonded. Comparative example no. In No. 8, the reduction ratio of aluminum was less than 10%, and some non-bonding occurred. Further, the shear strength is as low as 3.0 to 5.5 kgf/mm2.

[0023]

[Effects of the Invention] As detailed above, according to the present invention,
An aluminum clad steel plate with high and stable shear strength and excellent bondability can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a composite in which four circumferences of an insert material are attached to the surface of a base material and sealed among composites in Examples.

[Explanation of symbols]

1 Base material 2 Laminating material 3 Insert material 4. Four-periphery sealed part

Claims (2)

[Claims] Claim 1: When manufacturing an aluminum clad steel plate using aluminum or an aluminum alloy as a laminated material and a steel plate as a base material by a rolling joining method, aluminum, aluminum alloy, nickel, and nickel alloy are added between the laminated material and the base material. After producing a composite in which one or more of these are interposed as insert materials, this is
A method for producing an aluminum clad steel sheet with excellent bondability, which comprises heating to 0° C. or higher and lower than the melting temperature of aluminum, and rolling under conditions such that the rolling reduction of the laminated material is 10% or higher in at least one pass. 2. The method according to claim 1, wherein the four circumferences of the insert material are pasted onto the surface of the base material and sealed.