JPH08174238A - Production of metal clad material - Google Patents

Abstract

PURPOSE: To make joining strength in the width direction uniform by heating metal strip wound on a heating roll, detecting meandering of strip and executing pressure welding while preventing meandering with a heating roll inclined. CONSTITUTION: Clad stocks 3, 4 are sent out from uncoilers 6, 7. The stocks 3, 4 are heated by a heating roll 5, subjected to pressure welding by a rolling mill 1 to be produced to a clad material 8 and the clad material is coiled to a clad coiler 9. Meandering of stocks 3, 4 is detected by a meandering detector 10, the heating roll 5 is inclined in the horizontal direction and/or vertical direction to correct meandering. Meandering correction by the heating roll 5 has response faster than meandering correction by coil reels 6, 7. Heating by a heating furnace causes temp. deviation in the width direction at generation of meandering but the roll heating method does not generate temp. deviation. Thus, the clad material 8 is stably produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a clad material in which metal strips made of different materials are heated and superposed and rolled and joined by a rolling mill.

[0002]

2. Description of the Related Art A clad material formed by joining different kinds of metal plates has been used in various fields because of its properties which cannot be obtained from a single metal plate, and its demand is increasing. For example, a lightweight aluminum and a clad material made of stainless steel, which has excellent heat conductivity and excellent corrosion resistance, are suitable for a cooker or the like.

As a clad material production method suitable for mass production, there is a method in which two metal strips made of different materials are respectively heated, and they are continuously superposed and rolled and joined.

FIG. 2 is a view showing a conventional production line for a clad material of aluminum and stainless steel which is generally used.

The aluminum strip 13 unwound from the uncoiler 16 and the stainless strip 14 unwound from the uncoiler 17 are respectively heated by a heating furnace 15 and rolled and joined by a rolling mill 11 to form a clad material. Examples of heating means include heating by an electric furnace and induction heating.

In such a production line, meandering occurs in the metal strip at the start of rolling joining or during rolling joining. When the meandering occurs, the coil reels 16 and 17 and the guide roll 18 immediately before the rolling mill are tilted to correct the meandering, and the centering during the rolling is maintained.

[0007]

However, when meandering occurs at the start of rolling joining or during rolling joining, the above-mentioned coil reel type meandering correction method has a slow correction response, and the stripping in the heating device is made at the time of correction. The nonuniform heating causes a large temperature deviation in the strip width direction of the metal strip, and the temperature deviation caused by the heating continues until the time of roll joining. That is, in the case of controlling the meandering with the coil reel, when the meandering occurs, the metal strip runs at a position slightly out of the uniform heating zone in the heating device, and if the correction response is slow, a temperature deviation occurs in the metal strip. Further, when controlling the meandering with the guide rolls immediately before the rolling mill, the temperature drop of the strip may occur due to heat removal by the guide rolls, and the temperature required for joining may not be obtained,
If the joining becomes defective, the elongation rate differs between the joined portion and the non-joined portion, and further meandering occurs, resulting in a temperature deviation of the strip, which causes throttling. In this case, the heat may be removed by the guide rolls and the heating temperature may be raised, but this is not preferable because the metal strip is easily oxidized.

When two types of metal strips having such a temperature deviation are joined by rolling, the temperature deviation causes a significant non-uniformity of the rolling pressure in the sheet width direction within the roll gap, resulting in a high temperature portion of the metal sheet. This causes so-called drawing, in which the rolling load is larger than that in the low temperature portion and the elongation percentage in the high temperature portion is large.

Therefore, if there is a time lag between the heating and the meandering adjustment operation, the length in which the reduction occurs during rolling and joining may be long, which may lead to breakage, resulting in a significant decrease in productivity. If the joining temperature is not uniform in the width direction of the strip even if it does not break, the peel strength of the product is not constant and the yield is reduced.

[0010]

As a result of various experiments to solve the above problems, the present inventor has found that temperature deviation in the plate width direction caused by the meandering is minimized by simultaneously performing heating and meandering correction. Therefore, it was found that a clad material having excellent peel strength can be obtained by suppressing the occurrence of drawing and as a result, preventing the occurrence of drawing.

The present invention is based on the above findings,
The gist is that "in a method of heating and joining metal strips of different materials by a rolling mill, the metal strip is wound around a heating roll on the inlet side of the rolling mill and heated,
"Rolling and joining method for metal strips, characterized in that the meandering of the metal strips is detected and the heating rolls are tilted in the horizontal direction and / or the vertical direction to prevent the metal strips from meandering and perform the roll joining."

[0012]

Next, the reasons and functions for limiting the present invention as described above will be explained.

FIG. 1 is an overall view of a rolling joining apparatus for carrying out the method of the present invention. The case of manufacturing a clad material of aluminum and stainless steel will be described.

A heating roll 5 having a meandering adjustment function for performing meandering adjustment and heating of the rolling mill 1, the aluminum strip 3 of the clad material, and the stainless steel strip 4,
An aluminum uncoiler 6 for sending out an aluminum strip and a stainless strip at a predetermined speed, a stainless uncoiler 7, a clad coiler 9 for winding a clad material 8 at a predetermined speed, and a meandering detector 10.
It has.

FIG. 3 is a longitudinal sectional view showing an example of an induction heating type roll used for carrying out the method of the present invention.

Outer roll shaft 22a and inner roll shaft 22b
A bearing 24 provided between the outer shell 21 and
Is rotatable. An induction coil 26 is provided in a portion of the inner shell 25 facing the outer shell 21,
The outer shell generates heat, and the inside of the inner shell is hollow, and air is introduced from an air pipe 24 provided at the center of the roll shaft 22b to cool the inner shell.

FIG. 4 is a plan view of a heating roll provided with a meandering prevention device. The heating roll 21 is a hydraulic cylinder 20 that is generally used to prevent the metal strip from meandering.
It is equipped with a mechanism that tilts in the horizontal direction. In the figure,
The dotted line shows the state of tilting in the horizontal direction. In addition,
To prevent meandering, the roll may be tilted in the vertical direction, or may be tilted both in the horizontal direction and the vertical direction.

The meandering detection is preferably performed on the entrance side of the rolling mill, and can be detected by, for example, the photoelectric tube 10.

As shown in FIG. 1, the metal strip is wound around the heating roll in order to increase the contact area between the metal surface and the roll surface and improve the heating efficiency.

Next, the meandering of the metal strip is controlled by the heating roll at the same time as heating the metal strip by means of the heating roll. When the metal strip meanders before rolling or during rolling, the correction response is fast without temperature drop by the guide roll. This is because the meandering adjustment can be performed so that the temperature in the width direction of the metal strip does not become uneven. Also,
The meandering until correction does not cause non-uniform heating because it is meandering of the strip within the width of the heating roll.

[0021]

EXAMPLES The present invention will be specifically described below based on Examples.

With the roll bonding apparatus shown in FIG. 1, the plate thickness is 2.0 m.
m A1100 aluminum strip having a plate width of 500 mm and SUS304 stainless steel strip having a plate thickness of 0.6 mm and a plate width of 500 mm were heated to 450 and 480 ° C., respectively, and rolled and joined by a rolling mill 1. During rolling joining,
It was possible to detect the meandering by the photocell 10 and correct the meandering by a commonly used control device (not shown) to carry out rolling joining having substantially no meandering.

As a comparative example, aluminum having the above dimensions and stainless steel were joined by the apparatus shown in FIG. An electric furnace was used as the heating means, and the meandering correction was carried out by a coil system without temperature drop.

10 mm from the edge of the stainless steel strip and 25 m from that point on the entry side of the rolling mill during joining
The temperature was measured at five points at m-intervals to examine the temperature distribution in the plate width direction. The measurement results are shown in Table 1. The measured value indicates the value measured immediately after the occurrence of meandering and the start of meandering adjustment.

FIG. 5 shows the temperature measurement results of Table 1.

Table 2 shows the peel strength of the joined clad materials.

FIG. 6 illustrates the results of Table 2.

The peel strength test is conducted according to JISZ2247.
And the peel strength is 20 N / mm or more.
And less than 20 N / mm was evaluated as x. Therefore, in the evaluation
Those with a mark cannot be peeled off (the strength is so great that they do not peel off)
Alternatively, the bondability is 20 N / mm or more, and the bondability is sufficiently high.

In Test Nos. 6 to 10 in Table 1, the temperature deviation in the width direction was 65 ° C. for both aluminum and stainless steel.
It is higher than 40 ° C of test numbers 1-5. The test numbers 6 and 7 in Table 2 do not satisfy the peel strength of 20 N / mm or more because the temperature deviations of both aluminum and stainless steel became large.

That is, it is shown that the clad material which is uniform in the width direction can be manufactured when the temperature deviation in the width direction is reduced.

[0031]

As is clear from the above description, by simultaneously heating the strip and suppressing the meandering,
A clad material having a uniform joint strength in the width direction can be stably manufactured.

[Brief description of drawings]

FIG. 1 is a diagram of a rolling joining apparatus for carrying out the present invention.

FIG. 2 is a diagram of a conventional rolling joining device.

FIG. 3 is a view showing a vertical section of a processing roll.

FIG. 4 is a view showing a meandering correction roll.

FIG. 5 is a diagram showing a widthwise temperature distribution of stainless steel and aluminum.

FIG. 6 is a view showing a peel strength distribution in the width direction of a clad material.

[Explanation of symbols]

 1, 11 Rolling device 2, 18 Guide roll 3, 13 Aluminum strip 4, 14 Stainless steel strip 5 Heating roll 15 Heating device 6, 16 Aluminum uncoiler 7, 17 Stainless steel uncoiler 8 Clad material 9, 12 Clad coiler 10 Meandering detection vessel

Claims (1)

[Claims] 1. In a method of heating metal strips of different materials and rolling and joining them with a rolling mill, the metal strips are wound around a heating roll at the entrance side of the rolling mill to heat the metal strips, and the meandering of the metal strips is performed. A method for producing a metal clad material, which comprises detecting and tilting the heating roll in a horizontal direction and / or a vertical direction to prevent the metal strip from meandering and roll-bonding.