JPH038501A - Production of aluminum sheet having excellent surface gloss - Google Patents

Abstract

PURPOSE:To obtain the sheet having excellent surface gloss by continuously casting and rolling a molten metal contg. specific ratios of Si and Fe and consisting of the balance Al, then cleaning the sheet for a specific period of time with an alkaline soln. of specific pH before at least one pass of cold rolling, and then subjecting the sheet to the cold rolling. CONSTITUTION:The molten aluminum contg., by weight %, 0.02 to 0.8% Si and 0.05 to 1.0% Fe and consisting of the balance Al is subjected to the continuous casting and rolling. The molten metal is rolled to the band-shaped sheet having 2 to 10mm thickness. The sheet is cleaned for 1 to 300 seconds by the alkaline soln. of <=pH10 before at least one pass of the rolling during the cold rolling stage and thereafter, the sheet is subjected to the cold rolling. The cooling rate is increased to make cystallized matter generated at the time of the casting fine and device by executing the above-mentioned continuous casting and rolling, by which the surface quality is improved. The increase in the surface roughness and the degradation in the glossiness resulted from the nonuniform partition and distribution, at the time of rolling, of the oxide films formed on the surface at the time of the casting are prevented by the above-mentioned cleaning treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing an aluminum plate with excellent surface quality, particularly surface gloss, used for baffles, name plates 1, etc.

[Conventional technology and its issues]

Aluminum plates used for panels, name plates, etc. have traditionally been made of alloys such as JI51050.1100.
Excellent surface quality, especially surface gloss, is required. The manufacturing method of this aluminum plate includes homogenizing an ingot produced by continuous casting, hot rolling, cold rolling,
It is manufactured through an annealing process.

However, the aluminum plate manufactured by the above process is
Overall, the surface has low gloss, and streaks often occur on the surface, making it impossible to obtain satisfactory characteristics in cases with severe surface requirements such as name plates.

[Problem to be solved by the invention]

As a result of studies on the above-mentioned problems, the present invention has developed a manufacturing method capable of producing an aluminum plate with excellent surface gloss and, in particular, excellent surface quality with no streaks on the surface.

[Means and effects for solving the problems] The present invention provides S
i 0.02-0.8wt%, Fe 0.05-1
．． A molten aluminum containing 0 wt% and the remainder AN is continuously cast and rolled to form a strip plate with a thickness of 2 to 10 ffI11, and the strip plate is cold rolled at a point where at least I bath cold rolling is left. This is a method for producing an aluminum plate with excellent surface gloss, which is characterized by performing a cleaning treatment for 1 to 300 seconds with an alkaline solution having a pH of 10 or more, and then cold rolling.

That is, the present invention has discovered that an aluminum plate with excellent surface quality can only be obtained by making intermetallic compounds on the surface of the aluminum plate fine and cold rolling after sufficiently removing oxides and the like on the surface. It is something.

However, to explain the components of the aluminum plate of the present invention, first, Si works to improve the strength of the alloy and improve the formability, and furthermore, together with Fe, Si works to improve the strength of the alloy and improves the formability. −
It forms an Fe-3i-based intermetallic compound and has the effect of reducing the amount of solid solution of Fe, thereby making recrystallized grains finer and improving surface quality. 5ill is 0.02
If it is less than 0.8 wt%, the above effect cannot be obtained sufficiently.
If it exceeds t%, the moldability will decrease.

Fe improves the strength of the alloy and also improves the strength of the AN-Fe series and Aj! -It has the effect of forming Fe-3i-based intermetallic compounds and making recrystallization finer, but if the amount is 0
．． If it is less than 0.05 wL%, sufficient effect cannot be obtained;
If it exceeds t%, the amount of intermetallic compounds increases too much, resulting in poor moldability and further deterioration of surface gloss.

The above-mentioned Si and Fe are the basic components of the aluminum plate that is the subject of the present invention, and based on these components, CuXMg and Zn of 0.5iit% or less and 0.5iit% or less of CuXMg and Zn are added.
Additions of 3wt% or less of C, Zr, and Mn are preferable because they improve strength without affecting surface quality, and additions of 0.1wt% or less of Ti and B are preferred. The surface quality is further improved by miniaturization.

However, in the present invention, molten aluminum having the above components is continuously cast and rolled into a strip plate having a length of 2 to 10+ m, but the cooling rate is slow in the conventional DC casting method, and /! 1l-Fe system and A/! -Fe-
Because the 5i-based crystallized phase is coarse and sparsely distributed, coarse recrystallized grains are generated during hot rolling and cannot be eliminated during annealing, resulting in streaks on the surface of the finished plate and further crystallized phases. This was done in consideration of the fact that the surface gloss decreases due to coarsening, and in the present invention, by performing continuous casting and rolling, the cooling rate is increased to make the crystallized substances produced during casting fine and dense, thereby improving the surface quality. It is something.

Here, the plate thickness of the continuously cast rolled plate was set to 2 to 10 m because
If it is less than 2, cracks will occur in the board, and if it is less than 1,
This is because if it exceeds 0, the cooling rate during solidification will be too low and the crystallized matter cannot be made sufficiently fine.

In addition, as continuous casting and rolling methods, the commonly used Hunter method, 30 method, and other methods may be used (cooling rate is 100° (
:/see or more can be applied.

In the present invention, the continuous casting and rolling plate described above is finished by cold rolling. During this process, after at least one pass of cold rolling, a cleaning treatment is performed for 1 to 300 seconds with an alkaline solution of PHLO or higher. After that, it is finished by cold rolling.

The above cleaning treatment prevents the oxide film formed on the surface during continuous casting from being unevenly divided and distributed during rolling, increasing the roughness of the product surface and reducing gloss. Under these cleaning conditions, the concentration of the alkaline solution is PHI
If O or cleaning time is less than 1 second, the oxide film cannot be removed sufficiently, and if it exceeds 300 seconds, Ae will be dissolved excessively.
AI! Fe-based and Al-Fe-3i-based crystallized phases remain on the surface, degrading the surface quality.

The cleaning temperature is preferably in the range of 15 to 90"C, and the alkali used is NaOH, KOH, Ca (oHLt
etc., especially using 0.3-10% NaOH,
Good results are obtained when the treatment time is in the range of 5 to 60 seconds.

Furthermore, it is desirable to continue acid cleaning after the above-mentioned alkali cleaning.Acid cleaning has the effect of preventing the alkaline solution from remaining on the board surface and deteriorating the surface quality due to the neutralization effect of the alkali, and the alkali cleaning. Washing dissolves the crystallized phase that comes to the surface and prevents the loss of gloss.

However, since the surface of the plate subjected to the above-mentioned cleaning treatment has irregularities, it is then finished by performing cold rolling at least once. Therefore, alkaline cleaning is performed where at least one bath of cold rolling remains.

Note that the above cleaning treatment may be performed immediately after continuous casting and rolling.

[Example] An embodiment of the present invention will be described below.

A cold-rolled plate of 0.5 mm was produced using aluminum having the components shown in Table 1 through the steps shown in Table 2. In each case, the final pass was performed using the same rolling roll, and the glossiness and streak characteristics of the cold-rolled sheets obtained were visually determined. The results are shown in Table 3.

As is clear from these tables, it was confirmed that the aluminum plates according to the present invention had better gloss than those produced by the conventional method and the comparative examples, and were free from streaks.

〔effect〕

As explained above, according to the present invention, an aluminum plate with excellent surface quality can be obtained, which has a significant industrial effect.

Claims (3)

[Claims] (1) Si0.02-0.8wt%, Fe0.05-1
．． A molten aluminum containing 0 wt% and the remainder Al is continuously cast and rolled to form a strip plate with a thickness of 2 to 10 mm,
During the cold rolling process, the strip plate is subjected to a cleaning treatment for 1 to 300 seconds with an alkaline solution having a pH of 10 or higher after at least one pass of cold rolling, and then cold rolled. Excellent aluminum plate manufacturing method. (2) The molten aluminum further contains 0.5 wt% or less of C.
u, Mg, Zn and 0.3 wt% or less Cr, Zr,
The method for producing an aluminum plate with excellent surface gloss according to claim 1, characterized in that it contains Mn. (3) The molten aluminum further contains T of 0.1 wt% or less
The method for producing an aluminum plate with excellent surface gloss according to claim 1, characterized in that it contains i and B.