JPS63230856A - Manufacture of aluminum-alloy sheet - Google Patents

Abstract

PURPOSE:To manufacture a high-quality Al-alloy sheet having fine cast structure by a simple equipment with minimized number of stages, by working a molten Al alloy into a sheet metal by means of a double roll and further applying cooling, rolling, and ageing treatment to the above sheet metal or by subjecting the above sheet metal to isothermal rolling or to cold rolling. CONSTITUTION:A molten Al alloy in a vessel 8 is poured between the rapidly rotating rolls of a double roll-type continuous-casting machine 1 and cooled rapidly down to a temp. lower than the solution-heat-treating temp. of the Al alloy and slightly higher than process-annealing temp., 380-410 deg.C, so as to be formed into an Al-alloy sheet of 2.5-4mm thickness, and this sheet is cooled rapidly in a water tank 2 so as to be formed into a solution-heat-treated state, surface-polished 4, rolled to the required thickness by means of a cold-rolling mill 5, and further aged 6 so as to be formed into a heat treatment hardening-type Al-alloy sheet, or, the continuously cast Al-alloy sheet is rolled by means of an isothermal rolling mill 9 and further passed through a roll 10 for cooling and a surface polishing device 4 or the continuously cast Al-alloy sheet is passed through the roll 10 for cooling and the surface polishing device 4 and then cold-rolled to the required thickness by means of a finish-rolling mill 11 so as to be inexpensively formed into a nonheat treatment hardening-type Al-alloy sheet by simple equipment and process.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an energy-saving method for manufacturing aluminum alloy thin plates that yields high-quality products.

[Prior Art] Fig. 4 shows an example of a hot rolling process in a conventional method for producing an aluminum alloy thin plate.
The alloy ingot with a thickness of I11 or more is subjected to sufficient homogeneous annealing and face shaving to remove lagoon wrinkles and segregation layers (scalping b), and then preheated to 400-450°C in a preheating furnace C, It is roughly rolled to 8-12 mm using a high-level reversible rolling mill d, etc., and then rough-formed through an upcut e1 edge trimmer r, and then processed at 300-350°C by a 4-high reversible rolling mill 9 to form a 2.5- 5ani hot rolled, then
After being sufficiently cooled to a temperature that prevents scratches, it is again passed through an upcut e' and an edge trimmer f', where both ends are trimmed, and wound into a coil machine h to complete the hot rolling process.

FIG. 5 shows an example of the cold rolling process in the conventional method for manufacturing aluminum alloy thin sheets. The aluminum alloy thin sheets that have gone through the above-mentioned hot rolling process are passed through a four-stage rolling roller l at room temperature to meet the required requirements. It is cold-rolled to dimensions (0.25-0.75-1), and is then manufactured into a product through various processes according to product demand.

[Problems to be Solved by the Invention] However, in the above-described method for manufacturing aluminum alloy thin plates, internal stress is likely to occur in the alloy ingot manufactured by the continuous casting method, and cracks are likely to occur.

In addition, if the ingot is made larger to increase the productivity of the rolling process, the cooling rate of the ingot becomes slower, which tends to cause surface wrinkles, segregation, and coarse crystallization, and requires sufficient homogenization annealing and hot rough rolling. Reheating or excessive surface shaving is required. It is said that the homogenization annealing and reheating of the ingot consumes a large amount of thermal energy, and the face cutting can add as much as 172% of the casting cost. Currently, surface wrinkles and segregation layers during casting are removed by face milling, and coarse crystallized materials are fractured and dispersed during the rolling process to produce sound thin plates, but they have low cycle fatigue properties. Further improvements in quality are required from the viewpoints of corrosion resistance and corrosion resistance.

In view of the above-mentioned circumstances, the present invention saves labor in the hot rolling process, achieves energy saving and low cost, and achieves refinement of the cast structure and ultrafine dispersion of crystallized materials by rapid cooling during casting. Alternatively, this method is made to provide a high quality and low cost aluminum alloy thin plate by constant temperature rolling or cold rolling immediately after casting.

[Means for Solving the Problems] In the present invention, an aluminum alloy thin plate that is continuously cast by passing molten aluminum alloy through twin rolls is rapidly cooled to a temperature below the aging temperature, and then cold-rolled to a predetermined thickness. Either the aluminum alloy sheet is rolled and subjected to the required aging treatment to produce a heat-treated hardened aluminum alloy thin sheet, or the cast aluminum alloy thin sheet described above is constant-temperature rolled to produce a non-heat-treated aluminum alloy annealed sheet. Furthermore, a method of manufacturing a non-heat-treated aluminum alloy hard thin plate by cold rolling the above-mentioned cast aluminum alloy thin plate has been devised.

[Function] Therefore, in the present invention, since the molten aluminum alloy is directly rolled into a thin plate, defects such as surface wrinkles and segregation that occur in an alloy ingot do not occur, and the alloy ingot can be rolled to produce a thin plate. There is no need to carry out homogenization annealing or face milling at the time of production, and the solidification rate is fast, reducing the number of products to be produced and producing high-quality aluminum alloy thin sheets.

[Example] Hereinafter, an example of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows an embodiment of the present invention, in which 550-
Two cooling rollers with a diameter of 500 m rotating at 100 rp rotate the molten metal at, for example, 700-720°C at a temperature lower than the solution treatment temperature and slightly higher than the intermediate annealing temperature (
For example, a water tank 2 for rapidly cooling the thin plate discharged from the twin roll type high speed continuous thin plate casting machine 1 is arranged directly below the twin roll type thin plate high speed continuous casting machine 1 which is cooled to 380-410°C. A guide roll 3 for changing the direction of movement of the thin plate is provided at the thin plate outlet of the water tank 2, and a surface polishing device 4 for chemical polishing or mechanical polishing as required is provided behind the guide roll 3, and a surface polishing device 4 for polishing the thin plate as required. A cold rolling mill 5 is installed to achieve a thickness of
, and finally a coiling machine 7 for winding the thin plate. Note that 8 is a tundish for pouring molten aluminum alloy into the twin-roll type thin plate high-speed continuous casting machine (2).

When molten aluminum alloy with a water temperature of 700-720°C is poured from the tundish 8 into the twin-roll type high-speed continuous thin plate casting machine 1, the temperature drops to 380-41°C due to the cooling action of the casting machine 1.
At 0°C, it becomes an aluminum alloy thin plate with a thickness of 2.5 to 4II11 and is discharged from the twin roll type thin plate high speed continuous casting machine 1, but the solidification rate during this time is 3000 to 13000°C/s.
EC, the secondary dendrite arm basing has an extremely fine casting structure of 5 μm, and an aluminum alloy thin plate in which no coarse crystallized substances are observed can be obtained.

In addition, since the discharge temperature mentioned above is lower than the solution treatment temperature and slightly higher than the intermediate annealing temperature, when this is rapidly cooled in the water tank 2, the aluminum alloy thin plate becomes a solution treated state. It is in the same state as the aluminium alloy thin plate obtained at the final stage of the hot rolling process in the conventional method for producing an aluminum alloy thin plate described above.

The aluminum alloy thin plate in this state is polished as necessary by the surface polishing device 4, and after being rolled to the required thickness by the cold rolling mill 5, it is put into the aging treatment device 6 and subjected to aging treatment, resulting in an extremely homogeneous product. A heat treatment hardened aluminum alloy thin plate with high strength and high toughness is obtained.

FIG. 2 shows another embodiment of the present invention, in which a constant-temperature rolling mill 9 for rolling aluminum alloy thin plates while maintaining a predetermined constant temperature is disposed behind the above-mentioned high-speed continuous casting machine for aluminum alloy thin plates. A cooling roll 10 is provided at the thin plate outlet of the rolling mill 9, followed by a surface polishing bag W14,
Other aspects are the same as in the first embodiment.

As mentioned above, the temperature of the aluminum alloy thin plate discharged from the aluminum alloy thin plate high-speed continuous casting machine 1 is 311
Since 0-410°C is above the intermediate annealing temperature, when the aluminum alloy thin plate in this state is rolled with the constant temperature rolling mill 9,
Non-heat-treated aluminum alloy annealed thin sheets can be manufactured with high productivity.

FIG. 3 shows still another embodiment of the present invention, in which a system is installed directly below the above-described high-speed continuous aluminum alloy thin plate casting machine 1 for rapidly cooling the aluminum alloy thin plate discharged from the aluminum alloy thin plate high-speed continuous casting machine 1. A cooling roll 10 is provided, and a surface polishing device (chemical polishing tank) 4 and a finishing rolling mill 11 are provided behind the cooling roll 10, and other aspects are the same as in the first embodiment.

An aluminum alloy thin plate discharged from a high-speed continuous aluminum alloy thin plate casting machine 1 is rapidly cooled by a cooling roll 10, subjected to a surface polishing device 4 if necessary, and then made to the required thickness by a finishing mill 11. Heat-treated aluminum alloy hard thin sheets can be manufactured.

It should be noted that the present invention is not limited only to the above-described embodiments, and for example, the configurations of the surface polishing device, finishing rolling mill, etc. can be applied as necessary, without departing from the gist of the invention. Of course, various changes can be made.

[Effects of the Invention] Since the method for manufacturing an aluminum alloy thin plate according to the present invention has the above-described configuration, it can exhibit various excellent effects as described below.

<D Since an alloy ingot is not used, there is no need for a surface shaving process to remove surface wrinkles and segregation layers, and there is no need for a homogenization annealing furnace.

(ID) Compared to the production of ingots using continuous casting equipment, which is currently in practical use, a hot rolling process is unnecessary because a thin plate can be directly cast.

■ As a result of <D, <, it is possible to save energy, reduce costs, and make effective use of the factory area, resulting in many benefits.

■ Because the solidification rate is extremely high, even if crystallized substances occur, they are dispersed extremely finely, and the casting structure is also fine, making it possible to manufacture high-quality aluminum alloy thin sheets with high productivity.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of one embodiment of the method for manufacturing an aluminum alloy thin plate of the present invention, FIG. 2 is an explanatory diagram of another embodiment of the present invention, and FIG. 3 is an explanatory diagram of yet another embodiment of the present invention. Figure, 4th
The figure is an explanatory diagram of a hot rolling process in a conventional method for manufacturing an aluminum alloy thin plate, and FIG. 5 is an explanatory diagram of a cold rolling process in a conventional method for manufacturing an aluminum alloy thin plate. In the figure, l is a twin-roll type thin plate high-speed continuous casting machine, 2 is a water tank,
4 is a surface polishing device, 5 is a cold rolling machine, 6 is an aging treatment device, 7 is a coiling machine, 9 is a constant temperature rolling machine, and 10 is a cooling roll.

Claims (1)

[Claims] 1) An aluminum alloy characterized in that a thin plate is continuously cast by passing the molten aluminum alloy through twin rolls and cooling it to a temperature lower than the solution treatment temperature and slightly higher than the intermediate annealing temperature. Method of manufacturing thin plates. 2) Pass the molten aluminum alloy through twin rolls to continuously cast a thin plate while cooling it to a temperature lower than the solution treatment temperature and slightly higher than the intermediate annealing temperature, and cast the obtained aluminum alloy thin plate at a temperature below the aging temperature. A method for manufacturing a heat-hardened aluminum alloy thin plate, which is rapidly cooled to a certain temperature, then cold-rolled to a predetermined thickness, and subjected to a required aging treatment. 3) A non-heat treatment type in which molten aluminum alloy is passed through twin rolls and continuously cast into a thin plate while being cooled to a temperature lower than the solution treatment temperature and slightly higher than the intermediate annealing temperature, and the resulting aluminum alloy thin plate is isothermal rolled. Method for manufacturing aluminum alloy annealed sheet. 4) A thin plate is continuously cast by passing the molten aluminum alloy through twin rolls and cooling it to a temperature lower than the solution treatment temperature and slightly higher than the intermediate annealing temperature, and the obtained aluminum alloy thin plate is cold rolled. A method for manufacturing a heat-treated aluminum alloy hard thin plate.