JPS5811769A - Production of bright al alloy plate material having superior anodized surface - Google Patents

Abstract

PURPOSE:To prevent the generation of patterns on the surface of a bright Al alloy plate material in the anodization after hot rolling in the stage of producing said plate by subjecting the plate to preliminary rolling under specific conditions prior to the hot rolling. CONSTITUTION:An ingot of a bright Al alloy contg. (0.2-1.2)% Mg, (0.05-0.2)% Cu or further (0.05-0.45)% Mn is heated to >=570 deg.C, whereby it is homogenized and is aggregated and coarsened of intermetallic compds. Prior to hot rolling, the ingot is subjected to preliminary rolling at >=15% draft and <=350 deg.C, then it is hot-rolled to a plate material. Despite anodizing, such bright Al alloy plate material does not form belt-, line- or streak-like patterns that degrade aesthetic value on the surface.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a bright AA alloy plate material having an extremely beautiful treated surface after anodizing treatment.

Conventionally, Mg: 0.2 to 1.2%, Cu:
Contains 5 to 0.2% of o, o, and further contains M as necessary.
M alloy, which contains n: 0.05 to 0.45% and has a composition in which the remainder consists of Al and unavoidable impurities (the above weight %, hereinafter h means weight %), is excellent in chemical polishing. 525'7,5657. It is widely used as 5457 alloy.

When these bright Ai gold alloys are used, they are usually processed into plate materials, but this processing is performed on an ingot that has been homogenized at a temperature of 450°C or higher, and the hot rolling start temperature is 35°C.
0 to 550°C, hot rolling end temperature: 400°C or less to obtain a hot-rolled sheet material, and then, if necessary, cold-roll and intermediate annealing the hot-rolled sheet material to obtain a cold-rolled sheet material. This is done by doing this.

The resulting bright M alloy sheet material has good strength and formability in addition to brightness, so it can be used for cosmetic containers,
Writer case, fountain pen cap.

It is used in a wide range of applications, including hubcaps, radiator grills, and light reflectors.

On the other hand, these bright M alloy plates have a hard surface that is hard to scratch, stain resistant, and has anodized surfaces to improve corrosion resistance, making them transparent and of high quality. Forming a film is also used.

When a bright AQ alloy sheet material is subjected to anodizing treatment, the surface often has a band-like or striped shape.

Otherwise, a sliver-like pattern appeared, which significantly reduced the aesthetic value.

Therefore, from the above-mentioned viewpoint, the present inventors conducted research to eliminate any patterns that appear on the surface of bright A9 alloy sheet materials when anodized. When a bright AQ alloy ingot that has been previously homogenized at a temperature of 570°C or higher to aggregate and coarsen intermetallic compounds is pre-rolled under specific conditions, the resulting bright AQ alloy ingot is pre-rolled under specific conditions.
It was discovered that patterns do not appear on the surface of N alloy plate materials even if they are anodized.

Therefore, this invention was made based on the above findings, and includes Mg: 0.2 to 1.2%, cu: 0.0
5 to 0.2%, and if necessary, Mn: 0.
A bright M alloy ingot having a composition containing 05 to 0.45% and the remainder consisting of M and unavoidable impurities is subjected to normal conditions,
That is, when hot rolling is performed under the conditions of hot rolling start temperature: 350 to 550°C and hot rolling end temperature: 400°C or less to produce a bright M alloy hot rolled sheet, the above hot rolling is performed. First, homogenization treatment was performed at a temperature of 570°C or higher to aggregate and coarsen the intermetallic compounds, and then at a temperature of 350°C.
The following is a bright M with an excellent anodized surface by pre-rolling at a rolling reduction of 15 inches or more.
This method is characterized by obtaining an alloy plate material.

In addition, in the method of this invention, the homogenization treatment is carried out at 570°C.
Carrying out the process at a higher temperature will reduce Mgzsi and F in the casting structure.
This is to ensure good brightness by aggregating and coarsening intermetallic compounds such as e A1.3. In addition, the pre-rolling conditions were set as per the above-mentioned rule because even if the rolling temperature exceeds 350°C or the rolling reduction is less than 15 inches, the desired processing strain cannot be applied, and as a result, hot finishing cannot be achieved. The effect of accelerating recrystallization during the rolling process is low, and when anodizing is performed, an undesirable band-like or sliver-like pattern appears on the surface. Therefore, in order to obtain an excellent anodized surface while maintaining excellent brightness and workability as well as high strength, homogenization treatment at a high temperature of 570° C. or higher and rolling temperature are required.

Preliminary rolling is required at a temperature of 350° C. or lower and a rolling reduction of 15% or higher.

In addition, Ritun, who specified the composition of the M alloy ingot in the method of the present invention as described above, first of all, regarding Mg, if the Mg content is less than 0.2%, the desired strength and formability cannot be achieved.
It cannot be added to the alloy plate material, and on the other hand, if the content exceeds 1.2, the moldability will not be impaired, but the brightness will also deteriorate.
0.2 to 1.2%, and as for Cu, if the content is less than 0.05%, the desired excellent brightness cannot be secured on the surface of the M alloy plate material. On the other hand, if the content exceeds 0.2%, the surface color becomes yellow and the unique color tone of AQ itself cannot be obtained, so the content is set at 0.05 to 0.2%. Furthermore, Mn is a component that has the effect of suppressing the growth of recrystallized grains during annealing and improving workability, so it is included as necessary, especially when further workability is required. component, but if its content is less than 0.05%, the desired processability improvement effect cannot be obtained; on the other hand, 0.45%
If the content exceeds 0.05, the brightness will be impaired as in the case of Mg.
It was set at ~0.45%.

Next, the method of the present invention will be explained using examples and comparing with comparative examples.

EXAMPLE Molten AE alloys having the respective compositions shown in Table 1 are melted using the usual melting method, and cast into an ingot.The ingot is heated at the temperature also shown in Table 1. After applying homogenization treatment under the condition of holding for 24 hours, thickness: 44 mm x width:
The ingot was cut to a size of 200 mm x length: 300 mm, and both sides of the ingot were faceted to a thickness of 40 mm.The ingot was then pre-rolled under various conditions shown in Table 1. Subsequently, hot rolling was performed under the conditions of hot rolling start temperature: 420°C, hot rolling end temperature: 300°C, and the plate thickness:
This hot-rolled sheet material was further cold-rolled under normal conditions to obtain a cold-rolled sheet with a thickness of O, Sm11.Then, the sheet was rolled using a fine-grained bright surface finishing roll. Thickness: 0.4ii, and in order to further temper this cold-rolled sheet to H24 equivalent, the temperature: 400 ° C. was held for 10 seconds, forced air cooling heat treatment was performed, and finally after chemical polishing, film thickness: 5 μm
AQ alloy sheets 1 to 10 of the present invention and comparative M alloy sheets 1 to 5 were manufactured by performing the anodizing treatment.

In addition, the Ae alloy sheets 1 to 10 of the present invention were all manufactured under the homogenization treatment conditions and pre-rolling conditions in the method of the present invention, while the comparative Ae alloy sheets 1 to 5 were manufactured under the homogenization treatment conditions. Or, the pre-rolling conditions were manufactured under conditions outside the scope of the present invention (indicated by * in Table 1).

Next, the resulting Ag of the present invention, alloy plate materials 1 to 1
For O and comparative At alloy plates 1 to 5, tensile strength,
In addition to measuring the conical cup value, the occurrence of band-like patterns on the surface was observed, and the specular reflectance was also measured.

In addition, the occurrence of band-like patterns is determined by appearance, and those with a good appearance with no band-like patterns are marked with a 0 mark, those with a very slight band-like pattern that is acceptable as a product are marked with an ○, and those with a good appearance with no band-like patterns are marked with an ○ mark. Those exhibiting a band-like pattern were evaluated with an X mark.

Regarding the specular reflectance, the specular reflectance of a silver mirror is 98%.
The specular reflectance of the plate material was measured with respect to a silver mirror reference surface. These results are also shown in Table 1.

From the results shown in Table 1, the present invention M alloy plate materials 1 to 10
In both cases, by applying homogenization treatment and pre-rolling under specific conditions, there is no decrease in strength and workability.
While the appearance of patterns on the anodized surface is almost gone and the specular reflectance remains high, comparative M alloy sheet material 1゜4, which is not subjected to pretreatment after homogenization treatment under specific conditions, and Pre-rolling is performed after homogenization under specific conditions. Furthermore, in Comparative AQ alloy plate material 3 in which the homogenization treatment conditions were outside the range of the present invention, the occurrence of band-like patterns was slight, but the specular reflectance was significantly inferior.

As described above, according to the method of the present invention, high strength and good workability can be achieved by simply subjecting the ingot before hot rolling to preliminary rolling under specific conditions after homogenization treatment under specific conditions. Therefore, it is possible to produce a bright M alloy plate material which has many patterns such as strips and stripes on its surface when it is anodized.

Applicant: Mitsubishi Aluminum Corporation Agent Tomi 1) Kazuo

Claims (2)

[Claims] (1) Mg: 0.2-1.2%, Cu: 0.
After homogenizing an ε alloy ingot containing 05 to 0.2% and having a composition (weight% above) consisting of M and unavoidable impurities, it is hot-rolled to form an Al1 alloy. When producing hot-rolled sheet materials, the homogenization treatment is carried out at 570°C.
It is carried out at a temperature above to aggregate and coarsen the intermetallic compounds,
Furthermore, prior to the hot rolling, the temperature: 350°C or less,
A method for producing a bright M alloy sheet material having an excellent anodized surface, characterized by performing preliminary rolling at a rolling reduction of 15% or more. (2) Mg: 0.2-1.2%, Cu: o
, o 5 to 0.2%, and further Mn: 0.05
After homogenizing an AA alloy ingot containing ~0.45% and having a composition (more than % by weight) consisting of AA and unavoidable impurities, it is hot rolled to form an Ae alloy ingot. When producing rolled plate material, the homogenization treatment is performed using 5'i'O
℃ or higher to aggregate and coarsen the intermetallic compounds, and further, prior to the hot rolling, pre-rolling is performed at a temperature of 350℃ or lower and a rolling reduction of 15% or higher. Glitter AA with anodized surface
Method for manufacturing alloy plate materials.