JPH02200383A - Manufacture of aluminum clad material - Google Patents

Abstract

PURPOSE:To stably manufacture an Al clad material sheet of good quality with high efficiency by heating base metal with its contact with heating rolls and subjecting it to induction heating on this side of a rolling mill and heating it to the specific temperature on the inlet side of rolling rolls and then, cladding it by heated rolls. CONSTITUTION:An Al sheet (strip) 9 with <=1.5mm thickness is used as the base metal. Dissimilar metal sheets (strips) 10 and 10' are superposed on the surface thereof and clad continuously between rolls of the rolling mill 5 to manufacture clad material 13. At that time, the base metal 9 at least is brought into contact with the heating rolls 11 and heated thereby and further, heated to 300-450 deg.C by an induction heating coil 8 on this side and the inlet side of the rolling mill 5. Afterward, the base metal is clad by the heated rolling rolls 12. By this method. the Al clad material sheet is manufactured at the low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for stably manufacturing thin plate aluminum cladding materials of good quality at low cost on a continuous rolling line.

<Prior art and its challenges> In recent years, craft materials, which are made by combining different metals with different characteristics and combining the advantages of each, have been used for example in kitchen utensils, building materials, cases for cosmetics, automobile parts (malls, etc.), electronic materials, etc. However, when manufacturing cladding materials using the "rolling welding method," which is advantageous in terms of manufacturing efficiency and manufacturing cost, the method shown in Figure 6 or 7 is usually used. The method shown in the figure is adopted.

That is, FIG. 6 shows the payoff reel 11. From It to base material (
A strip (for example, aluminum) 2 and a strip of laminated material (for example, stainless steel) 3 are unwound and overlapped and heated by passing them through a heating furnace 4.
Fig. 7 is a schematic diagram showing the process of press-welding the clad material 6 into a clad material 6 and then winding it onto a take-up reel 7.
7 is a schematic diagram showing an outline of a process in which an induction heating coil 8 is used instead of the heating furnace 4 in FIG. 6. FIG.

However, when a heating furnace is used to heat the material as shown in Figure 6, the heat transfer rate is not good because the material is heated through the atmosphere or seal gas, and therefore a continuous rolling line requires a long rolling line. This required a heating furnace, which was a big disadvantage in terms of equipment space and equipment costs.

On the other hand, when an induction heating coil is used to heat the material as shown in Figure 7, rapid heating is possible and there is no particular inconvenience in terms of equipment space. It has been pointed out that thin plate materials tend to be heated more easily than other parts, resulting in a temperature difference between the width edges and the center, and that thin sheet materials can cause shape defects and cause narrowing.

Furthermore, in any of the above methods, when a thin aluminum plate with a thickness of 1.5 mm or less (particularly 11 m or less) is used as the base material, the bonding strength of the resulting aluminum crund material does not meet the intended value. It was also pointed out that there was no such thing.

Therefore, an object of the present invention is to provide a means for stably manufacturing thin plate aluminum cladding materials of good quality without shape defects or joint defects on a compact continuous rolling line at low cost. .

Means for Solving the Problems> This invention was completed through research conducted by the inventor through numerous experiments in order to achieve the above object. When producing a cladding material by overlapping dissimilar metal thin plates on the surface of the aluminum plate and continuously pressing them between rolling rolls, at least the base material is brought into contact with a heating roll and heated,
Furthermore, by induction heating before the rolling mill to bring the temperature at the entrance of the rolling rolls to 300-450°C, and then performing pressure welding with the heated rolling rolls, we can produce high-quality aluminum cladding and throat materials at low cost and stably. The point is that it can be manufactured in
It has the following characteristics.

Here, the types of dissimilar metals used as bonding materials are not particularly limited, and include stainless steel and carbon steel.

It may be made of titanium or titanium alloy.

Furthermore, the phrase "at least the base material is heated by bringing it into contact with a heating roll" means "the dissimilar metals used as the laminated materials may or may not be heated", for example, 5 tons.
It is okay to heat materials such as JS304 steel that do not have any particular effect on bondability even when heated to about 500℃, but
It is best not to heat materials such as carbon [, Ti, or 5US430 steel, which will form an oxide film and become difficult to bond when heated to high temperatures; It is preferable to keep it below.

The reason why the temperature at least on the entry side of the heating roll of the aluminum base material is limited to 300 to 450°C is that if the temperature is less than 300°C, it will be difficult to obtain a rad material with good bonding strength. This is because if the temperature exceeds 450°C, necking of the material tends to occur, making it unsuitable for actual production.

What is shown in FIG. 1 or FIG. 2 is an example of the method for manufacturing aluminum cladding and gutter materials according to the present invention, and is a three-layer cladding material in which an aluminum strip is used as a base material and strips of different metals are bonded to both sides of the aluminum strip. The present invention will be explained in detail below along with its operation based on the drawings.

Function> The aluminum clad material production line shown in FIG. The main feature is that a rolling roll 12 is used. First, in FIG. 1, the payoff reel 1
Aluminum strip 9 unwound from zero and dissimilar metal strip 1 unwound from payoff reel 1□, 1°
0.10" are each wrapped around a heating roll 11 and subjected to solid contact heating, then stacked in three layers, and then further auxiliary heated by an induction heating coil 8 to a temperature of 300 to 450°C.
The heated rolling roll 12 of the rolling mill 5 is heated while maintaining the temperature of .
It is supplied between 12 and rolled and crimped. The three-layer clad material 13 after being crimped is then wound onto the take-up reel 7.

On the other hand, Fig. 2 shows a method of rolling and crimping a heated aluminum strip by overlapping a dissimilar metal strip without heating, and the aluminum strip 9 unwound from a payoff reel 1° is 1
1 and subjected to solid contact heating, and furthermore, the temperature at the entrance of the rolling mill is maintained at 300 to 450°C by the induction heating coil 8.
The process proceeds with supplementary heating so that the payoff frills 1□, 1. Dissimilar metal strip 10 rewound from
10' is directly superimposed on the heated aluminum strip 9 without heating. Then, the aluminum strip 9 and the dissimilar metal strip 10 are superimposed.
．． 10' refers to the heated rolling roll 12 of the rolling mill 5 in this state.
．． The three-layer cladding material 13 is supplied between the three-layer cladding material 12 and crimped, and the three-layer cladding material 13 after the crimping is wound up on a winding wheel 7.

Now, as explained earlier, in the conventional method explained using Figs. 6 and 7, problems that cannot be ignored have been pointed out in terms of heating efficiency, heating furnace installation space, local heating temperature deviation, etc. However, in the heating method of the present invention, which involves wrapping a material strip around a heating roll, it has a good heat transfer coefficient, so large equipment is not required, and uniform heating in the width direction of the material sheet can be performed sufficiently, so it is easy to use in a continuous line. Extremely convenient for heating strip materials.

However, if the material is a thin plate, there is a problem in that even if the material is heated by a heating roll, it is likely to be cooled down immediately, and the temperature will drop by the time it is sent to the rolling mill.

However, in the present invention, the induction heating coil 8 is disposed on the inlet side of the rolling mill to reheat the material, so that the required minimum temperature on the inlet side of the rolling mill is effectively ensured.

Here, the reason why induction heating means is used to reheat the material is as follows.
In order to prevent the temperature of the material heated by wrapping it around the heating roll from dropping, it is best to reheat it just before the pressure roll.Compact induction heating means are most suitable for reheating the material just before the rolling roll, where there is little space, and it is thermally efficient. It's also good. In this case, since the material is preheated by roll heating, there is no need to input a large amount of electric power, and the temperature deviation between the widthwise end portion and the center portion is also small, so that shape defects will not occur.

Furthermore, if the material heated to the required temperature by the induction heating coil 8 is rolled as usual, especially in the case of a thin plate material, a sudden temperature drop will occur due to heat being removed to the rolls in the gap between the rolling rolls. Although there was also a problem that the joint strength became unstable, this problem can be effectively solved by installing a hot rolling roll 12 in the rolling mill to reduce heat loss to the roll. However, it is not necessary to apply this hot rolling slot 12 to both the upper and lower rolls, and it may be applied only to one side where a large amount of heat is expected to be removed.

Here, when the rolling rolls are in direct contact with the aluminum base material as in the production of two-layer cladding materials, heating to high temperatures may cause seizure, so the rolling rolls located on the aluminum base metal side are heated. When the heating is 1
It is preferable to keep the temperature below 00°C.

By the way, the thickness of the aluminum base material to which the method of the present invention is applied is as follows:
The reason for limiting the thickness to 1.5 m or less is that if the thickness of the aluminum base material is thicker than 1.5 m, there will be less temperature drop due to heat radiation, and reheating by induction heating immediately before the mill and heating rolling rolls will be easier. This is because it is possible to manufacture a cladding material with desired strength even without using it. Note that if the base material is too thin, necking (width shrinkage) tends to occur at the entrance of the rolling mill, but this tendency is determined by the maximum temperature of the base material, the tension at that position, and the strip width, so it is especially important to set the lower limit value. Although it cannot be limited, it is best to keep in mind a lower limit of approximately 0.5 sm or less.

As a "heating roll" for heating the strip material, it is preferable to use a roll with an internal induction coil that generates heat by itself or a heat-generating roll that is heated from the inside with a burner. As the rolling roll, it is preferable to use a hollow roll equipped with an Elema heater or the like inside.

Of course, in addition to the three-stage heating process of heating by wrapping the material around a heating roll, reheating with an induction heating coil, and using a hot rolling roll to reduce heat loss, as shown in Figure 3, In addition, a heating furnace 4 is used to preheat the material.
Needless to say, it is good to install an induction heating coil.

Next, the present invention will be explained in more detail with reference to Examples.

(Example) First, a pure aluminum coil (base material), a stainless steel coil (laminated material), and a pure titanium coil (laminated material), each having a width of 180 mm and a thickness shown in Table 1, were prepared.

Next, as shown in FIG. 4, payoff reel 1. .

After unwinding the pure aluminum strip 14 and the stainless steel strip or the pure titanium strip 15 from the pure aluminum coil and the stainless steel coil or the pure titanium coil attached to the coils 12 and passing them through the brush device 16, only the aluminum strip 14 is transferred to the heating roll 11. After passing through an induction heating coil and reheating it (no induction heating for some of the comparative examples), an unheated stainless steel strip or pure titanium strip 15 is superimposed on it and passed through a rolling mill 5. The aluminum cladding material obtained by feeding and rolling was wound up on a winding wheel 7.

Here, for one example (example 2 of the present invention), the stainless steel strip serving as the laminated material was also heated with a heating roll (not shown).
The aluminum cladding material was obtained by wrapping the aluminum cladding material around the material and heating it, and the subsequent steps were carried out in the same manner.

In addition, during rolling, only the rolling rolls located on the stainless steel strip or pure titanium strip 15 side were heated rolls, and the rolling rolls located on the aluminum strip side were non-heated rolls.

The bonding state of the aluminum clad material thus obtained was investigated, and the results are shown in Table 1 together with the clad material manufacturing conditions.

The bonding condition was investigated by a torsion test. In this tear test, a test piece with the dimensions shown in Fig. 5(a) was cut out from an aluminum clad material, and a torsion test was performed as shown schematically in Fig. 5(b). After inserting the test piece 17 into the test device, first turn the handle 18 to the right four times to stain the test piece, then reverse the handle 18 to return it to its original position, and then turn it to the left four times this time. hand(
In other words, the test method is to apply reverse tearing (4 rotations to the right + 8 rotations to the left) and examine the presence or absence of peeling at this time.

As is clear from the results shown in Table 1, in examples that satisfy the conditions stipulated by the present invention, aluminum cladding materials with good bonding properties can be stably manufactured even from thin plate materials. It can be confirmed that the products obtained in the comparative examples whose manufacturing conditions do not meet the provisions of the present invention are inferior in quality.

Summary of Effects> As explained above, the present invention brings about industrially useful effects such as being able to stably produce high-quality thin aluminum cladding materials with high efficiency.

[Brief explanation of the drawing]

1 to 3 are schematic diagrams each illustrating an example of manufacturing an aluminum clad material according to the present invention. FIG. 4 is a schematic diagram illustrating the main equipment used in the example. FIG. 5 is an explanatory diagram of the torsion test applied in the example.
Figure (b) shows the torsion testing machine. FIGS. 6 and 7 are schematic diagrams illustrating examples of conventional clad material production, respectively. In the drawings, 1o, L, 1□, 1. ...Payoff reel. 2...Base material strip. 3... Laminated material strip, 4... Heating furnace. 5... Rolling mill, 6... Clad material. 7... Take-up reel, 8... Induction heating coil. 9.14...Aluminum strip. 10.10'...Dissimilar metal strip. 11...Heating roll, 12...Heating rolling roll. 13...3-layer cladding material. 15... Stainless steel strip or pure titanium strip. 16... Brush device, 17... Test piece. 18...handle.

Claims (1)

[Claims] When manufacturing a cladding material by using an aluminum plate with a thickness of 1.5 mm or less as a base material and continuously pressing different metal thin plates over the surface of the aluminum plate between rolling rolls, at least the base material is heated by heating rolls. In addition to contacting and heating,
A method for producing an aluminum clad material, which further comprises performing induction heating before the rolling mill to bring the temperature at the entrance of the rolling roll to 300 to 450°C, and then performing pressure welding with the heated rolling roll.