JP2000301294A - PRODUCTION OF HYPER-EUTECTIC Al-Fe BASE ALLOY CONTINUOUSLY CAST AND ROLLED COIL - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a coil obtd. by continuously casting a hyper-eutectic Al-Fe base alloy to be made extremely thin in thickness to a specified thickness or below by further applying cold-rolling, and to prevent the occurrence of defect such as pin hole. SOLUTION: In this producing method, the hyper-eutectic Al-Fe base alloy containing 1.7-3.2 wt.% Fe is continuously cast and rolled to 2 mm-4.5 mm thickness under condition of 680-780 deg.C molten metal temp. and >=7 KN/mm of the width. Further, the cold-rolling is applied to obtain the continuously cast and rolled coil for producing the aluminum alloy thin sheet having <=100 μm thickness.

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 continuously cast and rolled hypereutectic Al--Fe alloy having excellent rollability, and more particularly to a method for cold rolling to a thickness of 100 .mu.m or less. The present invention relates to a method for producing a hypereutectic Al-Fe alloy continuous cast and rolled coil.

[0002]

2. Description of the Related Art When an Fe component is added to an aluminum alloy, strength and heat resistance are improved, so that an Fe component is often added to an aluminum alloy foil or an aluminum alloy fin material. Since the solid solution amount of Fe in the aluminum alloy is small, when DC (die casting) casting is performed, a coarse intermetallic compound containing Fe is generated at the time of casting, which has an adverse effect on formability and the like. Therefore, as a manufacturing method for increasing the cooling rate and miniaturizing intermetallic compounds generated at the time of casting, a continuous casting and rolling method for directly manufacturing a sheet thinner than about 10 mm from a molten aluminum alloy is performed. In the continuous casting and rolling method, the cooling rate at the time of casting is high, so that the F content is not less than 1 wt% (hereinafter, wt% is simply referred to as%).
It is possible to refine the intermetallic compound even with an aluminum alloy to which e is added, and the strength of the obtained alloy is high, which is suitable for thinning the fin material. In addition, since the heat resistance is high, foil rolling is performed. Sometimes it is difficult to soften due to the heat generated during processing, and the foil rollability is improved. However, in order to further improve the characteristics, Fe is further added, and the hypereutectic Al-F
When using e-based alloy, 100μm from continuous casting coil
In the following, when the material is rolled to an extremely thin thickness, pinholes may be generated, and in the case of a more severe material, the material may break during rolling before reaching a thickness of 100 μm, and may not be rolled.

[0003]

Accordingly, the present invention provides
A coil obtained by continuous casting from a hypereutectic Al-Fe alloy can be extremely thinned to a thickness of 100 μm or less by cold rolling, and can prevent the occurrence of defects such as pinholes. It is an object of the present invention to provide a method for producing a continuous cast-rolled coil of a monocrystalline Al-Fe alloy.

[0004]

SUMMARY OF THE INVENTION The present invention provides a continuous casting and rolling method for producing a hypereutectic Al-Fe alloy coil which can be rolled to a thickness of 100 μm or less, which can be used as a foil or a fin material. It was made about. That is, the present invention provides (1) a hypereutectic Al-Fe-based alloy containing 1.7% or more and 3.2% or less Fe at a molten metal temperature of 680 ° C.
A continuous cast and rolled coil for manufacturing an aluminum alloy thin plate having a thickness of 100 μm or less, wherein the coil is continuously cast and rolled to a thickness of 2 mm or more and 4.5 mm or less while applying a load of 7 kN or more per 1 mm width at a temperature of not less than 780 ° C. 2. A continuous cast and rolled coil for manufacturing an aluminum alloy sheet according to claim 1, wherein (2) the temperature of the molten metal is higher than the liquidus temperature of the alloy by a temperature range of 40 ° C. or more and 90 ° C. or less. And (3) hypereutectic Al-Fe
The base alloy is made of 1.2% or less of Si, 3.0% or less of Co,
0.3% or less Zr, 0.3% or less Ti, 6% or less Zn, 0.3% or less In, 0.3% or less Sn, 1%
(1) A hypereutectic Al-Fe alloy containing one or more of Cu, Mn of 1.3% or less, and Mg of 1% or less and inevitable impurities.
Another object of the present invention is to provide a method for producing a continuous cast and rolled coil for producing an aluminum alloy sheet as described in (2).

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The manufacturing method of the present invention will be described below. The present invention is directed to a hypereutectic Al-Fe alloy. This is because a thin plate having excellent properties cannot be produced from the alloy by a normal DC casting method or a conventional continuous casting and rolling method.
Here, the reason why the Fe content is set to 1.7% or more and 3.2% or less is that when the Fe content is less than 1.7%, the coil can be manufactured under the conventional continuous casting and rolling conditions. In addition, 3.2%
If the temperature exceeds 300 ° C., the alloy cannot be supercooled to the eutectic temperature during casting, and even if the method of the present invention is used, a sheet that can be rolled to a sheet having a thickness of 100 μm or less may not be obtained.
Is set to 3.2%. The lower limit of the amount of Fe that becomes hypereutectic varies slightly depending on other elements added together. However, there is a variation in manufacturing a molten metal industrially.
When it is 7% or more, the method of the present invention is effective. The hypereutectic Al-Fe-based alloy may contain various elements depending on the use of the finally obtained thin plate, etc., within a range that does not impair the effects of the present invention. For example, 1.2% or less of Si, 3.0% or less of Co, 0.3% or less of Zr, 0.
3% or less Ti, 6% or less Zn, 0.3% or less I
n, 0.3% or less of Sn, 1% or less of Cu, 1.3% or less of Mn, or 1% or less of Mg, and may contain unavoidable impurities. These elements exhibit important functions in terms of characteristics when mainly forming an alloy into a foil or a fin material. Within the above range, the production method of the present invention can be applied. However, in order to reduce the generation of intermetallic compounds described below and to suppress cracking during casting of the alloy, each is 0.7% or less. Si, 2.0% or less Co, 0.2% or less Zr, 0.2% or less Ti, 2%
Zn below, In below 0.1%, S below 0.1%
n, Cu of 0.5% or less, Mn of 0.6% or less, 0.3
% Of Mg is preferable.

According to the present invention, the above alloy melt is heated to a temperature of 6
At a temperature of 80 ° C. or more and 780 ° C. or less, a load of 7 kN or more per 1 mm of width (width) is applied, and a thickness of 2 mm to 4.5 m is applied.
m and continuous casting and rolling. Hypereutectic Al used in the present invention
Conventionally, in the case of an Fe-based alloy, an intermetallic compound containing Fe, such as an Al-Fe system, is crystallized as a primary crystal during continuous casting and rolling. Cracks and the like occur during rolling. Incidentally, in the manufacturing process of DC casting, since the cooling rate at the time of DC casting is lower than that of continuous casting and rolling, an intermetallic compound having a size incomparable with that of continuous casting and rolling is generated, and pinholes and cracks occur at the time of rolling. Here, the molten metal temperature is 68
If the temperature is less than 0 ° C., the solidification state during continuous casting and rolling changes easily due to subtle changes in conditions such as subtle temperature variations on the roll surface because the molten metal temperature is close to the solidus temperature of the alloy. It is presumed that the properties of the material are changed. On the other hand, when the temperature exceeds 780 ° C., the cooling capacity of the continuous casting and rolling mill is insufficient, and an intermetallic compound containing Fe is formed at the center in the sheet thickness direction, which causes pinholes and cracks, and also has an energy problem. Is also useless. Here, the molten metal temperature is defined as the temperature of the head box of the casting machine.
The head box is provided immediately before the molten metal is supplied to the nozzle, and is a part for pooling the molten metal in order to stably supply the molten metal.

For the above reasons, the temperature of the molten metal is set to 680 ° C. to 78
In the present invention, it is recommended that the temperature of the molten metal be higher than the liquidus temperature of the alloy by a temperature range of 40 ° C. or more and 90 ° C. or less. When the temperature difference between the molten metal temperature and the liquidus temperature is less than 40 ° C., the molten metal of the continuous casting and rolling is cooled at the nozzle portion for supplying the molten metal between the rolls, and an Fe-containing intermetallic compound is generated. And flows into the plate material as it is, causing pinholes and cracks. Further, when the temperature of the molten metal exceeds 90 ° C. from the liquidus line, the molten alloy cannot be supercooled to the eutectic temperature, and hypereutectic Al-Fe-based intermetallic compounds are generated coarsely at the beginning of cooling. This causes pinholes and cracks. Hypereutectic Al at such a temperature
-Continuous casting and rolling of the molten Fe-based alloy to a thickness of 2 mm or more and 4.5 mm or less under a load of 7 kN or more per 1 mm in width.

As the thickness of the continuous casting and rolling is larger, defects such as a surface and the like generated during the continuous casting and rolling are less and troubles are less likely to occur. Therefore, about 5 mm to 10 mm is generally used industrially. Hypereutectic Al as the subject of the present invention
In the case of an Fe-based alloy, if the thickness is large, a normal coil can be manufactured without apparent defects, but cracks and pinholes are generated in the cold rolling process. This is hypereutectic Al-Fe
In the case of a system alloy, an intermetallic compound containing Fe such as an Al-Fe system may be crystallized as a primary crystal, but if the thickness of continuous casting and rolling is large, the entire alloy is supercooled and does not solidify. , The intermetallic compound segregates at the center in the thickness direction of the plate,
It is considered that the aggregation state of the intermetallic compound causes cracks and pinholes to be easily generated in the cold rolling step. If the thickness during continuous casting exceeds 4.5 mm, the supercooling is insufficient and segregation of the intermetallic compound is likely to occur. On the other hand, if the thickness is less than 2 mm, cracks and sheet thickness fluctuations occur at the time of continuous casting and rolling, and it is not possible to manufacture a coil to be used for subsequent cold rolling.

In manufacturing a continuous cast rolled coil having such a thickness, it is necessary to manufacture the coil under a condition of applying a load of 7 kN or more per 1 mm in width. The load in the conventional continuous casting and rolling is about 3 kN / mm, but the reason for applying a load exceeding this is as follows. In the conventional method, when the rolling load is less than 7 kN / mm, the solidification interface 1,
As shown in FIG. 1A, solidification 2 is completed at a position near the center axis of the roll (the center of the casting). On the other hand, under the conditions of the present invention, solidification is completed at a position far from the center axis of the roll. Further, the solidification interface in FIG. 1 (A) is schematically shown from the cross-sectional direction, and the solidification interface in the plate width direction when viewed from above is indicated by 1, 2 in FIG. 1 (B).
It has a wavy shape as shown in Fig. The magnitude of this wave increases as the rolling load decreases. If the rolling load is too small, that is, if the rolling load is less than 7 kN / mm, Fe is concentrated in the unsolidified liquid phase at the interface portion where solidification is completed at a position close to the roll central axis in such waving. It is considered that super-cooling is unlikely to occur due to the increased localization of the Fe component locally due to the concentrated Fe, so that intermetallic compounds caused by hypereutectic Fe are generated densely. This aggregation of intermetallic compounds causes cracks and pinholes during cold rolling. As described above, in the present invention, continuous casting and rolling is performed by applying a load of 7 kN or more per 1 mm in width, but the upper limit is set to a limit determined by equipment of a continuous casting and rolling device.

Here, the continuous casting and rolling method is a hunter method,
This is a method of casting and rolling an aluminum alloy known by the 3C method and the like, and is sometimes referred to as direct rolling. The continuous cast and rolled coil manufactured in the present invention is for cold rolling to make a thin plate of 100 μm or less. Since this invention solves the problem that occurs when rolling to 100 μm or less, it is naturally possible to roll as a material having a thickness exceeding 100 μm, but the metal structure obtained under the manufacturing conditions of the present invention is required in terms of characteristics. Unless otherwise, it is not usually necessary to use coils manufactured under the conditions of the present invention. The production conditions of the present invention are for producing a thin plate under a special rolling load condition by a continuous casting and rolling method, and the productivity may be reduced (because a high load makes it difficult to produce a wide plate). is there. In cold rolling the coil manufactured under the conditions of the present invention, annealing may be performed during or before and after the cold rolling step.

[0011]

The present invention will be described in more detail with reference to the following examples. Each aluminum alloy No. having the composition shown in Table 1 was used.
From A, B, and C, coils of each thickness were produced under the continuous casting and rolling conditions in Table 2. Table 2 also shows the liquidus temperatures of the alloys. The roll diameter of the continuous casting and rolling equipment used is 618 m
m and the width of the manufactured coil is 800 mm. After annealing the obtained coil at 360 ° C. for 2 hours, a coil for a fin material having a thickness of 0.06 mm was manufactured by the steps of cold rolling, annealing, and cold rolling, and the obtained coil was reduced to a width of 16 mm. Slitter processed. 6m cold rolling pass schedule
m → 2.4mm → 1mm → 0.5mm → 0.3mm →
0.18 mm → 0.11 mm → 0.06 mm, and the thickness of the first rolling pass differs depending on the thickness of the first continuous cast rolling coil. Table 3 shows the state of the cold rolling and the state of the slitter processing.

[0012]

[Table 1]

[0013]

[Table 2]

[0014]

[Table 3]

From the results shown in Table 3, it was found that, in the case of using the present invention, rolling could be performed up to 0.06 mm, but in Comparative Examples having different conditions, rolling could not be performed on the way, or fracture occurred during slitting. Here, Comparative Example 5 is a condition used in continuous casting and rolling of a conventional general aluminum alloy (an alloy that is not hypereutectic).

[0016]

As described above, in the present invention, hypereutectic Al-F
A rolled thin plate of an e-based alloy can be manufactured, and this has a remarkable industrial effect.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a solidification state in continuous casting and rolling. FIG. 1B is a schematic diagram when FIG. 1A is viewed from above.

[Explanation of symbols]

 Reference Signs List 1 solidification interface 1 (when load is small) 2 solidification interface 2 (when load is large) 3 continuous casting and rolling roll surface 4 roll center axis

Claims (3)

[Claims] 1. An F content of not less than 1.7 wt% and not more than 3.2 wt%.
e-containing hypereutectic Al-Fe alloys at a molten metal temperature of 6
7kN per 1mm width at 80 ℃ or more and 780 ℃ or less
A method for producing a continuous cast and rolled coil for producing an aluminum alloy sheet having a thickness of 100 μm or less, wherein the above-mentioned load is applied to continuously cast and roll to a thickness of 2 mm or more and 4.5 mm or less. 2. The temperature of the molten metal is set at 40 ° C. below the liquidus temperature of the alloy.
The method for producing a continuous cast and rolled coil for producing an aluminum alloy sheet according to claim 1, wherein the temperature is raised by a temperature range of 90 ° C or less. 3. A hypereutectic Al—Fe-based alloy containing 1.2 wt.
% Si or less, 3.0 wt% or less Co, 0.3 wt%
Zr below, Ti below 0.3 wt%, Zn below 6 wt%, In below 0.3 wt%, S below 0.3 wt%.
n, 1 wt% or less Cu, 1.3 wt% or less Mn,
The continuous casting for manufacturing an aluminum alloy sheet according to claim 1 or 2, wherein the alloy is a hypereutectic Al-Fe-based alloy containing one or more kinds of Mg of not more than wt% and unavoidable impurities. Manufacturing method of rolled coil.