JPH11217656A - Production of aluminum alloy foil excellent in foil rollability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an aluminum alloy foil excellent in foil rollability at a low cost. SOLUTION: This method is a method of manufacture of an aluminum alloy foil, where an aluminum alloy ingot haying a composition consisting of, by weight, 0.2-2.8% Fe, 0.05-0.3% Si, and the balance Al with inevitable impurities is subjected to homogenizing heat treatment, hot rolling, and cold rolling in this order, and the hot rolled plate thickness is regulated to <=3 mm and the temp. after at least final pass of cold rolling is regulated to 100 to 180 deg.C. Because the foil excellent in foil rollability can be produced by controlling cold rolling conditions, this method has the tremendous advantage in costs over the conventional method where process annealing is performed between cold rolling stages and also the date of product delivery can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method of manufacturing an aluminum alloy foil excellent in foil rollability at low cost.

[0002]

2. Description of the Related Art Aluminum foil has a thickness of about 5 to 200 [mu] m and is mainly used for packaging foodstuffs, medicines and the like. This aluminum foil is often used by being laminated with polyethylene, vinyl, paper, resin or the like. Depending on the contents to be packaged, it is necessary to shield the contents of the aluminum foil from atmospheric moisture and ultraviolet rays, and aluminum foil used for such applications is required to be excellent in quality. And such aluminum foil is mainly JIS-1N30, JIS-1050, J
Pure aluminum such as IS-1100 is used. The aluminum foil is formed by casting a molten aluminum into a slab by a semi-continuous casting method, and subjecting the slab to a homogenizing heat treatment, hot rolling, cold rolling, and intermediate annealing to a thickness of 0.3 mm.
It is manufactured by forming a foil material (plate material) having a thickness of up to 0.6 mm and further rolling this foil material into a foil having a thickness of 5 to 200 μm. This rolling from the foil base to the foil is called foil rolling.

[0003]

In recent years, it has been required to reduce the cost of the aluminum foil, and as one of the measures, the elimination of intermediate annealing in the cold rolling process has been studied. If the intermediate annealing can be omitted, energy costs and annealing equipment will not be required, and productivity will be improved. Therefore, it will be extremely advantageous in terms of cost, and the production lead time will be shortened. However, simply omitting the intermediate annealing results in excessive work hardening during cold rolling, resulting in frequent foil breakage during foil rolling, reducing productivity, and from foil to final foil. However, there is a problem that the total cost of manufacturing the foil is high. From these facts, the present inventors have studied diligently about a method in which foil rolling can be favorably performed even if intermediate annealing is omitted, and by controlling the pass rise temperature in cold rolling to a high temperature, the foil rolling property is improved. And found that the present invention was completed by further research. An object of the present invention is to provide a method for manufacturing an aluminum alloy foil excellent in foil rollability at low cost without intermediate annealing.

[0004]

According to the present invention, Fe is contained in an amount of 0.2.
To 2.8% by weight (hereinafter abbreviated as%),
A method for producing an aluminum alloy foil, comprising subjecting an aluminum alloy ingot containing 5 to 0.3% and the balance of Al and unavoidable impurities to homogenization heat treatment, hot rolling and cold rolling in this order, The thickness after rolling is set to 3 mm or less, and the temperature at least in the final pass of cold rolling is set to 100 to 1
This is a method for producing an aluminum alloy foil excellent in foil rollability, which is controlled at 80 ° C.

[0005]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, the alloy element Fe
Is crystallized as an Al-Fe intermetallic compound during casting. Then, in the next hot rolling step, the recrystallized grains are refined as nuclei. Further, the crystallized product is uniformly dispersed as particles having a size of 1 to 5 μm by hot rolling and cold rolling, and contributes to improvement in foil strength. In the present invention, the content of Fe is 0.2 to
The reason for specifying 2.8% is that if it is less than 0.2%, the effect cannot be sufficiently obtained, and if it exceeds 2.8%, the effect is saturated and the corrosion resistance is lowered. Alloying element Si
Contributes to the improvement of strength in coexistence with Fe. If the content of Si is less than 0.05%, the effect cannot be sufficiently obtained.
If it exceeds 0.3%, the amount of solid solution of Si increases, and the work hardening in foil rolling becomes excessive, so that a large number of pinholes are generated in the foil. Therefore, the content is defined as 0.05 to 0.3%. In the present invention, impurity elements such as Cu, Mn, Mg, and Zn may be contained as long as their amounts are about 0.05% or less. Ti or B is effective in refining the solidification structure during semi-continuous casting and rolling, and is added in an amount of about 0.1% or less as necessary.

In the present invention, if the thickness after hot rolling exceeds 3 mm, the work hardening of the foil material becomes excessive and the foil rollability decreases. Therefore, the thickness is specified to be 3 mm or less.
In the present invention, if the hot-rolled material is made to have a recrystallized structure by raising the hot-rolling finish temperature to a high temperature, the strength of the foil base after the next cold rolling is reduced, and the foil rollability is improved. The hot rolling finish temperature is desirably 300 ° C. or higher.

[0007] The present invention is to control the rise temperature of at least the final pass of cold rolling to a predetermined high temperature to promote the recovery of the work structure of the foil, and thereby improve the foil rollability.
If the pass rise temperature is less than 100 ° C., the recovery of the processed structure is insufficient and the foil rollability is not sufficiently improved.
If it exceeds, lubrication failure occurs and surface defects such as herringbone occur. Therefore, at least the final pass rise temperature of the cold rolling is set to 100 to 180 ° C. Especially 120
~ 160 ° C is desirable. Surface defects such as the herringbone cause pinholes. The pass-up temperature in the cold rolling is set to 10 for the passes other than the final pass.
It is desirable to control the temperature to 0 to 180 ° C. to promote the recovery of the processed structure.

[0008] The pass rise temperature in cold rolling is increased mainly by the heat generated during processing. For example, in the case of a pure aluminum alloy of the 1000 series having a small heat generated by processing, it is 60 ° C.
９０90 ° C. The pass rise temperature in the cold rolling is 1
As a method of controlling the temperature to 00 to 180 ° C., high-speed rolling, rolling under high pressure, performing the next rolling immediately after cold rolling, rolling with a tandem rolling mill having two or more stands, coiling A method such as rolling with a reversible continuous rolling reverse rolling mill without change is effective. In addition, there is also a method of controlling the amount of coolant by restricting it.
It is applicable within a range that does not deteriorate the surface quality of the foil material.

[0009]

The present invention will be described below in detail with reference to examples. (Example 1) An aluminum alloy having the composition specified in the present invention shown in Table 1 was melt-cast by a conventional method to form an ingot. The hot rolled sheet having a thickness of 1.7 to 2.9 mm was formed by cold rolling, and the hot rolled sheet was subjected to cold rolling in two to three passes to produce a foil material having a thickness of 0.35 mm. No intermediate annealing was performed in cold rolling. The thickness of the hot-rolled sheet and the temperature at which the pass was raised during cold rolling were variously changed within the range of the present invention. The pass rise temperature in the cold rolling was changed according to the cold rolling entry side temperature, the cold rolling reduction ratio, the cold rolling speed and the like shown in Tables 1 and 2.

(Comparative Example 1) The thickness of the hot-rolled sheet was 1.7-8.
0 mm, the number of cold rolling passes was set to 2 to 4 times, and the thickness of the hot-rolled sheet and the rise temperature of the cold rolling pass were variously changed outside the scope of the present invention. Otherwise, a foil material was manufactured in the same manner as in Example 1.

Each of the foil substrates produced in Example 1 and Comparative Example 1 was foil-rolled to a thickness of 15 μm (four passes), and further doubling-rolled to obtain a foil having a thickness of 6 μm. For each of the obtained foils, the number of pinholes and the number of foil breaks during foil rolling were examined. The same investigation was performed on a conventional foil manufactured by inserting intermediate annealing during cold rolling. Table 2 shows the results.

[0012]

[Table 1] (Note) Cost disadvantage due to conventional method and intermediate annealing (see Table 2).

[0013]

[Table 2] (Note) Conventional method, intermediate annealing conditions: sheet thickness 0.75 mm, 340 ° C x 4 hours.

As is clear from Table 1, No. 1 of the present invention example
No. 6 to No. 6 showed little foil breakage and the number of pinholes during foil rolling, and showed foil rollability equivalent to that of No. 12 of the conventional method. No. 12 of the conventional method has a high cost because the intermediate annealing is performed in the middle of the cold rolling, and the production delivery time is long. On the other hand, in Nos. 7 and 8 of the comparative examples, the pass-up temperature in the cold rolling was low, and in No. 9, the hot rolled sheet was thick. In Nos. 10 and 11, a large number of pinholes were generated due to surface defects such as herringbone due to the high pass-up temperature during cold rolling.

[0015]

As described above, according to the present invention, since a foil material excellent in foil rollability is manufactured by controlling the cold rolling conditions, the conventional method of manufacturing by performing intermediate annealing during cold rolling. As compared with the above, it is remarkably advantageous in terms of cost, the production lead time can be shortened, and industrially remarkable effects are exhibited.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C22F 1/00 694 C22F 1/00 694B 694Z

Claims (1)

[Claims] 1. An Fe content of 0.2 to 2.8% by weight (hereinafter referred to as%
Aluminum alloy foil containing 0.05 to 0.3% of Si and the remainder being subjected to homogenization heat treatment, hot rolling and cold rolling in the order of an aluminum alloy ingot consisting of Al and unavoidable impurities. An aluminum alloy foil excellent in foil rollability, characterized in that the hot-rolled sheet thickness is 3 mm or less and at least the final pass rise temperature of cold rolling is controlled to 100 to 180 ° C. The method of manufacturing the ground.