TWI383053B - Method for fabricating aluminum alloy thick plate and aluminum alloy thick plate - Google Patents

Description

Aluminum alloy thick plate manufacturing method and aluminum alloy thick plate

The present invention relates to a method for producing an aluminum alloy thick plate and an aluminum alloy thick plate.

In general, an aluminum alloy material such as an aluminum alloy thick plate is used for various purposes. For example, it includes a semiconductor related device such as a base substrate, a conveying device, a vacuum device chamber, a motor electronic component and a manufacturing device thereof, a living article, a mechanical component, and the like.

Such an aluminum alloy material is generally produced as follows. In other words, the aluminum alloy of the raw material is melted and cast to produce an ingot, and if necessary, a homogenization heat treatment is performed, and then the ingot is rolled to a predetermined thickness (for example, refer to paragraphs 0037 to 0045 of Patent Document 1).

Further, regarding the mold material used for the die for press, the following materials are used. That is, steel, cast steel, etc. are used as the amount of production, and zinc alloy cast materials, aluminum alloy cast materials, and the like are used as test effects. In recent years, there has been a tendency to reduce the amount of a large number of products, and as a medium-sized production, a rolled material such as a rolled material or a forged material of an aluminum alloy has been popularized.

Patent Document 1: Japanese Laid-Open Patent Publication No. 2005-344173

However, the above-described method for producing an aluminum alloy material by rolling has the following problems.

(1) A method of rolling after casting, regarding the surface state and flatness of the rolled sheet (especially the flatness in the longitudinal direction), which is performed only by a calender roll, and is formed on the surface of the rolled sheet by hot calendering. A thick oxide film makes it difficult to control the surface condition and flatness.

(2) Since the calender roll does not easily control the thickness of the sheet, it is difficult to improve the sheet thickness precision. Further, in the central portion in the thickness direction, the size of the intermetallic compound is increased, and when the alumite treatment is performed, the cross section and the surface in the thickness direction are likely to be uneven. Further, in the case where the ingot is subjected to rolling, as the number of rolling increases, the number of working steps is increased, resulting in an increase in cost.

The present invention has been made in view of the above problems, and an object thereof is to provide a method for manufacturing an aluminum alloy thick plate which has excellent productivity, can easily control surface state and flatness, and can improve plate thickness precision, and provides a surface state. Aluminum alloy thick plate with excellent flatness and plate thickness accuracy.

The first invention of the present invention is a method for producing an aluminum alloy thick plate from an aluminum alloy, characterized in that the aluminum alloy contains Mg: 1.5% by mass to 12.0% by mass, and contains Si: 0.7% by mass or less. Fe: 0.8% by mass or less, Cu: 0.6% by mass or less, Mn: 1.0% by mass or less, Cr: 0.5% by mass or less, Zn: 0.4% by mass or less, Ti: 0.1% by mass or less, and Zr: 0.3% by mass or less At least one of the foregoing, the remainder being composed of Al and unavoidable impurities; and sequentially performing the following steps: a melting step of melting the aluminum alloy, a dehydrogenation step of removing hydrogen from the molten aluminum alloy, and removing hydrogen from the molten aluminum alloy a step of filtering the aluminum alloy to remove the inclusions, a casting step of casting the aluminum alloy after removing the inclusions into an ingot, A step of cutting the aluminum alloy thick plate having a predetermined thickness by cutting the ingot, and a heat treatment step of heat-treating the aluminum alloy thick plate having a predetermined thickness by maintaining the temperature at 400 ° C or higher and not reaching the melting point for 1 hour or more.

The second invention of the present invention is a method for producing an aluminum alloy thick plate from an aluminum alloy, characterized in that the aluminum alloy contains Mn: 0.3% by mass to 1.6% by mass and contains Si: 0.7% by mass or less. Fe: 0.8% by mass or less, Cu: 0.5% by mass or less, Mg: 1.5% by mass or less, Cr: 0.3% by mass or less, Zn: 0.4% by mass or less, Ti: 0.1% by mass or less, and Zr: 0.3% by mass or less At least one of the foregoing, the remainder being composed of Al and unavoidable impurities; and sequentially performing the following steps: a melting step of melting the aluminum alloy, a dehydrogenation step of removing hydrogen from the molten aluminum alloy, and removing hydrogen from the molten aluminum alloy a step of filtering the aluminum alloy to remove the inclusions, a casting step of casting the aluminum alloy from which the inclusions are removed into an ingot, a step of cutting the ingot and manufacturing the aluminum alloy thick plate having a predetermined thickness, and a predetermined thickness The aluminum alloy thick plate is subjected to a heat treatment step of heat treatment at a temperature of 400 ° C or higher and a temperature not exceeding the melting point for 1 hour or more.

The third invention of the present invention is a method for producing an aluminum alloy thick plate from an aluminum alloy, characterized in that the aluminum alloy contains Si: 0.2% by mass to 1.6% by mass, and Mg: 0.3% by mass to 1.5% by mass. Further, it is selected from the group consisting of Fe: 0.8% by mass or less, Cu: 1.0% by mass or less, Mn: 0.6% by mass or less, Cr: 0.5% by mass or less, Zn: 0.4% by mass or less, Ti: 0.1% by mass or less, and Zr: 0.3 mass. At least one of % or less, the remainder being composed of Al and unavoidable impurities; and the following steps are carried out in sequence: a melting step of melting the aluminum alloy, and a molten aluminum after melting a hydrogen removal step for removing hydrogen from gold, a filtration step for removing inclusions from an aluminum alloy after removing hydrogen, a casting step of casting an aluminum alloy from which inclusions are removed into an ingot, and cutting the ingot to produce aluminum having a predetermined thickness The heat-treating step of heat-treating the alloy thick plate by holding the aluminum alloy thick plate of a predetermined thickness at a temperature of 400 ° C or more and not reaching the melting point for 1 hour or more.

The fourth invention of the present invention is a method for producing an aluminum alloy thick plate from an aluminum alloy, characterized in that the aluminum alloy contains Mg: 0.4% by mass to 4.0% by mass, and Zn: 3.0% by mass to 9.0% by mass. Further, it is selected from the group consisting of Si: 0.7% by mass or less, Fe: 0.8% by mass or less, Cu: 3.0% by mass or less, Mn: 0.8% by mass or less, Cr: 0.5% by mass or less, Ti: 0.1% by mass or less, and Zr: 0.25 mass. At least one of % or less, the remainder being composed of Al and unavoidable impurities; and sequentially performing the following steps: a melting step of melting the aluminum alloy, and a hydrogen removal step of removing hydrogen from the molten aluminum alloy, a step of removing the inclusions from the aluminum alloy after removing the hydrogen, a casting step of casting the aluminum alloy from which the inclusions are removed into an ingot, and a step of cutting the ingot to produce a thick aluminum alloy plate having a predetermined thickness, and A heat treatment step in which a predetermined thickness of an aluminum alloy thick plate is heat-treated at a temperature of 350 ° C or more and less than the melting point for 1 hour or more.

In the first to fourth inventions described above, it is preferable to adopt the following configuration.

(A) After the aforementioned heat treatment step, a surface smoothing treatment step is performed to perform surface smoothing treatment on the surface of the aluminum alloy thick plate. In the above configuration, the surface smoothing treatment is preferably carried out by one or more methods selected from the group consisting of a cutting method, a grinding method, and a polishing method.

(B) in the cutting step, the central portion in the thickness direction is removed from the ingot; the central portion in the thickness direction has a uniform thickness from the center in the thickness direction toward each surface in the thickness direction, and the thickness of the ingot is T In the case of a total, it has a thickness of T/30~T/5.

According to a fifth aspect of the invention, there is provided a method for producing an aluminum alloy thick plate from an aluminum alloy, characterized in that the aluminum alloy contains Mg: 1.5% by mass to 12.0% by mass and contains Si: 0.7% by mass or less Fe: 0.8% by mass or less, Cu: 0.6% by mass or less, Mn: 1.0% by mass or less, Cr: 0.5% by mass or less, Zn: 0.4% by mass or less, Ti: 0.1% by mass or less, and Zr: 0.3% by mass or less At least one of the foregoing, the remainder being composed of Al and unavoidable impurities; and sequentially performing the following steps: a melting step of melting the aluminum alloy, a dehydrogenation step of removing hydrogen from the molten aluminum alloy, and removing hydrogen from the molten aluminum alloy a step of filtering the aluminum alloy to remove the inclusions, a casting step of casting the aluminum alloy after removing the inclusions into an ingot, and a heat treatment for heat treatment by holding the ingot at a temperature of 200 ° C or more and less than 400 ° C for 1 hour or more. The step of cutting the heat-treated ingot to produce a cutting step of an aluminum alloy thick plate having a predetermined thickness.

According to a sixth aspect of the invention, there is provided a method for producing an aluminum alloy thick plate from an aluminum alloy, characterized in that the aluminum alloy contains Mn: 0.3% by mass to 1.6% by mass, and contains Si: 0.7% by mass or less Fe: 0.8% by mass or less, Cu: 0.5% by mass or less, Mg: 1.5% by mass or less, Cr: 0.3% by mass or less, Zn: 0.4% by mass or less, Ti: 0.1% by mass or less, and Zr: 0.3% by mass or less At least one of them, the remainder being composed of Al and unavoidable impurities; and the following steps are carried out in sequence: a melting step of melting the aluminum alloy, a dehydrogenation step of removing hydrogen from the molten aluminum alloy, a filtration step of removing inclusions from the aluminum alloy after removing the hydrogen, and a casting step of casting the aluminum alloy from the inclusion into the ingot A heat treatment step of heat-treating the ingot at a temperature of 200 ° C or more and less than 400 ° C for 1 hour or more, and cutting the ingot after heat treatment to produce a cutting step of an aluminum alloy thick plate having a predetermined thickness.

According to a seventh aspect of the invention, there is provided a method for producing an aluminum alloy thick plate from an aluminum alloy, characterized in that the aluminum alloy contains Si: 0.2% by mass to 1.6% by mass, and Mg: 0.3% by mass to 1.5% by mass; Further, it is selected from the group consisting of Fe: 0.8% by mass or less, Cu: 1.0% by mass or less, Mn: 0.6% by mass or less, Cr: 0.5% by mass or less, Zn: 0.4% by mass or less, Ti: 0.1% by mass or less, and Zr: 0.3 mass. At least one of % or less, the remainder being composed of Al and unavoidable impurities; and sequentially performing the following steps: a melting step of melting the aluminum alloy, and a hydrogen removal step of removing hydrogen from the molten aluminum alloy, a step of removing the inclusions from the aluminum alloy after removing the hydrogen, a casting step of casting the aluminum alloy from which the inclusions are removed into an ingot, and holding the ingot at a temperature of 200 ° C or higher and less than 400 ° C for 1 hour or more. A heat treatment step of heat treatment and a step of cutting the heat-treated ingot to produce a thick aluminum alloy plate having a predetermined thickness.

The eighth invention of the present invention is a method for producing an aluminum alloy thick plate from an aluminum alloy, characterized in that the aluminum alloy contains Mg: 0.4% by mass to 4.0% by mass, and Zn: 3.0% by mass to 9.0% by mass. Further, it is selected from the group consisting of Si: 0.7% by mass or less, Fe: 0.8% by mass or less, Cu: 3.0% by mass or less, Mn: 0.8% by mass or less, Cr: 0.5% by mass or less, and Ti: 0.1. At least one of mass% or less and Zr: 0.25 mass% or less, and the remainder is composed of Al and unavoidable impurities; and the following steps are sequentially performed: a melting step of melting the aluminum alloy, and a molten aluminum a dehydrogenation step of removing hydrogen from the alloy, a filtration step of removing the inclusions from the aluminum alloy after removing the hydrogen, a casting step of casting the aluminum alloy after removing the inclusions into an ingot, and the ingot is less than 350 ° C at 200 ° C or higher The heat treatment step of maintaining the temperature for 1 hour or more and the step of cutting the ingot after the heat is cut to produce a thick aluminum alloy plate having a predetermined thickness.

In the fifth to eighth inventions described above, it is preferable to adopt the following configuration.

(C) After the cutting step, a surface smoothing treatment step is performed to perform surface smoothing treatment on the surface of the aluminum alloy thick plate of a predetermined thickness. In the above configuration, the surface smoothing treatment is preferably carried out by one or more methods selected from the group consisting of a cutting method, a grinding method, and a polishing method.

(D) in the cutting step, the central portion in the thickness direction is removed from the ingot; the central portion in the thickness direction has a uniform thickness from the center in the thickness direction toward each surface in the thickness direction, and the thickness of the ingot is T In the case of a total, it has a thickness of T/30~T/5.

According to a ninth aspect of the invention, there is provided a method for producing an aluminum alloy thick plate from an aluminum alloy, characterized in that the aluminum alloy contains Mg: 1.5% by mass to 12.0% by mass and contains Si: 0.7% by mass or less Fe: 0.8% by mass or less, Cu: 0.6% by mass or less, Mn: 1.0% by mass or less, Cr: 0.5% by mass or less, Zn: 0.4% by mass or less, Ti: 0.1% by mass or less, and Zr: 0.3% by mass or less At least one of them, the remainder being composed of Al and unavoidable impurities; and the following steps are carried out in sequence: a melting step of melting the aluminum alloy, a dehydrogenation step of removing hydrogen from the molten aluminum alloy, a filtration step of removing inclusions from the aluminum alloy after removing the hydrogen, and a casting step of casting the aluminum alloy from the inclusion into the ingot A step of cutting the aluminum alloy thick plate having a predetermined thickness by cutting the ingot, and a heat treatment step of heat-treating the aluminum alloy thick plate having a predetermined thickness at a temperature of 200 ° C or more and less than 400 ° C for 1 hour or more.

According to a tenth aspect of the invention, there is provided a method for producing an aluminum alloy thick plate from an aluminum alloy, characterized in that the aluminum alloy contains Mn: 0.3% by mass to 1.6% by mass, and contains Si: 0.7% by mass or less Fe: 0.8% by mass or less, Cu: 0.5% by mass or less, Mg: 1.5% by mass or less, Cr: 0.3% by mass or less, Zn: 0.4% by mass or less, Ti: 0.1% by mass or less, and Zr: 0.3% by mass or less At least one of the foregoing, the remainder being composed of Al and unavoidable impurities; and sequentially performing the following steps: a melting step of melting the aluminum alloy, a dehydrogenation step of removing hydrogen from the molten aluminum alloy, and removing hydrogen from the molten aluminum alloy a step of filtering the aluminum alloy to remove the inclusions, a casting step of casting the aluminum alloy from which the inclusions are removed into an ingot, a step of cutting the ingot and manufacturing the aluminum alloy thick plate having a predetermined thickness, and a predetermined thickness The aluminum alloy thick plate is subjected to a heat treatment step of heat treatment at a temperature of 200 ° C or more and less than 400 ° C for 1 hour or more.

The eleventh invention of the present invention is a method for producing an aluminum alloy thick plate from an aluminum alloy, characterized in that the aluminum alloy contains Si: 0.2% by mass to 1.6% by mass, and Mg: 0.3% by mass to 1.5% by mass. Further, it is selected from the group consisting of Fe: 0.8% by mass or less, Cu: 1.0% by mass or less, Mn: 0.6% by mass or less, Cr: 0.5% by mass or less, and Zn: 0.4% by mass or less, Ti: At least one of 0.1% by mass or less and Zr: 0.3% by mass or less, and the remainder is composed of Al and unavoidable impurities; and the following steps are carried out in sequence: a melting step of melting the aluminum alloy, and after melting a dehydrogenation step of removing aluminum gas from an aluminum alloy, a filtration step of removing inclusions from an aluminum alloy after removing hydrogen, a casting step of casting an aluminum alloy from which inclusions are removed into an ingot, and cutting the ingot to have a predetermined thickness The step of cutting the aluminum alloy thick plate, and heat-treating the aluminum alloy thick plate of a predetermined thickness at a temperature of 200 ° C or more and less than 400 ° C for 1 hour or more to perform heat treatment.

According to a twelfth aspect of the invention, there is provided a method for producing an aluminum alloy thick plate from an aluminum alloy, characterized in that the aluminum alloy contains Mg: 0.4% by mass to 4.0% by mass, and Zn: 3.0% by mass to 9.0% by mass, Further, it is selected from the group consisting of Si: 0.7% by mass or less, Fe: 0.8% by mass or less, Cu: 3.0% by mass or less, Mn: 0.8% by mass or less, Cr: 0.5% by mass or less, Ti: 0.1% by mass or less, and Zr: 0.25 mass. At least one of % or less, the remainder being composed of Al and unavoidable impurities; and sequentially performing the following steps: a melting step of melting the aluminum alloy, and a hydrogen removal step of removing hydrogen from the molten aluminum alloy, a step of removing the inclusions from the aluminum alloy after removing the hydrogen, a casting step of casting the aluminum alloy from which the inclusions are removed into an ingot, and a step of cutting the ingot to produce a thick aluminum alloy plate having a predetermined thickness, and The heat treatment step of heat treatment is performed for a predetermined thickness of the aluminum alloy thick plate at a temperature of 200 ° C or more and less than 350 ° C for 1 hour or more.

In the ninth to twelfth inventions described above, it is preferable to adopt the following configuration.

(E) After the aforementioned heat treatment step, a surface smoothing treatment step is performed to perform surface smoothing treatment on the surface of the aluminum alloy thick plate. In the above configuration, the surface smoothing treatment is preferably carried out by one or more methods selected from the group consisting of a cutting method, a grinding method, and a polishing method.

(F) in the cutting step, the central portion in the thickness direction is removed from the ingot; the central portion in the thickness direction has a uniform thickness from the center in the thickness direction toward each surface in the thickness direction, and the thickness of the ingot is T In the case of a total, it has a thickness of T/30~T/5.

The thirteenth invention of the present invention is characterized in that the aluminum alloy thick plate produced by the method for producing an aluminum alloy thick plate according to any one of the first to twelfth inventions has an average crystal grain size of 400 μm or less. .

In the first to fourth inventions described above, since the content of the predetermined element of the aluminum alloy is limited to a predetermined range, the refinement and strength of the intermetallic compound of the aluminum alloy thick plate can be improved. Further, since the hydrogen gas is removed by the dehydrogenation step, the concentration of hydrogen in the ingot can be limited, and even if the crystal grains in the ingot are coarsened, hydrogen accumulation and concentration do not occur at the grain boundary near the surface of the ingot. The bulging of the ingot is suppressed, and the rolling up of the swelled aluminum alloy slab is suppressed, and the potential defect of the slab surface which will form the surface defect of the slab can be suppressed. It can also increase the strength of aluminum alloy thick plates. The inclusions such as oxides and non-metals are removed from the aluminum alloy by a filtration step. Further, the ingot is cut by the cutting step, so that the thickness of the oxide film can be reduced, and the surface state, flatness, and thickness precision of the aluminum alloy thick plate can be improved, and productivity can be improved. Further, by heat-treating the aluminum alloy thick plate by heat treatment, the internal stress can be removed and the internal structure can be made uniform.

Therefore, according to the first to fourth inventions described above, the strength of the aluminum alloy thick plate can be improved. Further, since the ingot is cut to produce an aluminum alloy thick plate, it is not necessary to reduce the thickness by hot rolling as in the prior art, and the work step can be omitted, so that productivity can be improved. Further, it is possible to suppress the unevenness of the surface and the cross section of the thick plate (uneven color tone), and to improve the flatness, the appearance property after the treatment of the aluminum oxide film, and the thickness accuracy. Moreover, since the aluminum alloy thick plate of a predetermined thickness after cutting is heat-treated at a temperature of 400 ° C (or 350 ° C) to a temperature less than the melting point, the internal stress can be removed and the internal structure can be uniformized, and good flatness and a plate can be obtained. Thickness and strength.

According to the above configuration (A), the surface state and flatness of the aluminum alloy thick plate can be further improved. Further, by smoothing the surface, the gas accumulation on the surface of the thick plate disappears, and when the aluminum alloy thick plate is applied to the chamber for the vacuum device, the vacuum degree of the chamber can be increased.

According to the above configuration (B), the central portion of the ingot which is likely to be uneven in the surface and the cross section of the aluminum alloy thick plate after the alumite treatment is obtained, and therefore, it is obtained, and has an excellent appearance after the treatment of the aluminum oxide film. Aluminium alloy thick plate. It can also reduce the staggering situation in the batch.

In the fifth to eighth inventions described above, since the content of the predetermined element of the aluminum alloy is limited to a predetermined range, the refinement and strength of the intermetallic compound of the aluminum alloy thick plate can be improved. Further, since the hydrogen gas is removed by the dehydrogenation step, the concentration of hydrogen in the ingot can be limited, and even if the crystal grains in the ingot are coarsened, hydrogen accumulation and concentration do not occur at the grain boundary near the surface of the ingot. The bulging of the ingot is suppressed, and the rolling up of the swelled aluminum alloy slab is suppressed, and the potential defect of the slab surface which will form the surface defect of the slab can be suppressed. also Can improve the strength of aluminum alloy thick plates. The inclusions such as oxides and non-metals are removed from the aluminum alloy by a filtration step. Moreover, the ingot is heat-treated by the heat treatment step, so that the internal stress can be removed and the internal structure can be uniformized. Further, the ingot is cut by the cutting step, so that the thickness of the oxide film can be reduced, and the surface state, flatness, and thickness accuracy of the aluminum alloy thick plate can be improved, and productivity can be improved.

Therefore, according to the fifth to eighth inventions described above, the balance between the flatness, the strength, and the machinability of the aluminum alloy thick plate can be improved. In other words, since the heat treatment of the ingot at a temperature of not more than 400 ° C (or 350 ° C) of 200 ° C or more can prevent the ductility from becoming high, the machinability (cutting fracture property) is not deteriorated, and the inside can be obtained. Removal of stress and homogenization of internal organization. Therefore, good flatness and thickness accuracy can be achieved. It can maintain strength. Further, since the ingot is cut and manufactured into an aluminum alloy thick plate, the thickness can be reduced by hot rolling without being conventionally known, and the work step can be omitted, so that productivity can be improved. Further, it is possible to suppress the unevenness of the surface of the thick plate section (uneven color tone), and to improve the flatness, the appearance property after the treatment of the aluminum oxide film, and the thickness accuracy.

According to the above configuration (C), the surface state and flatness of the aluminum alloy thick plate can be further improved. Further, by smoothing the surface, the gas accumulation on the surface of the thick plate disappears, and when the aluminum alloy thick plate is applied to the chamber for the vacuum device, the vacuum degree of the chamber can be increased.

According to the above configuration (D), the central portion of the ingot which is likely to be uneven in the surface and the cross section of the aluminum alloy thick plate after the alumite treatment is obtained, so that it can be obtained and has an excellent appearance after the treatment of the aluminum oxide film. Sex Aluminum alloy plate. It can also reduce the staggering situation in the batch.

In the above-described ninth to twelfth inventions, since the content of the predetermined element of the aluminum alloy is limited to a predetermined range, the refinement and strength of the intermetallic compound of the aluminum alloy thick plate can be improved. Further, since the hydrogen gas is removed by the dehydrogenation step, the concentration of hydrogen in the ingot can be limited, and even if the crystal grains in the ingot are coarsened, hydrogen accumulation and concentration do not occur at the grain boundary near the surface of the ingot. The bulging of the ingot is suppressed, and the rolling up of the swelled aluminum alloy slab is suppressed, and the potential defect of the slab surface which will form the surface defect of the slab can be suppressed. It can also increase the strength of aluminum alloy thick plates. The inclusions such as oxides and non-metals are removed from the aluminum alloy by a filtration step. Further, the ingot is cut by the cutting step, so that the thickness of the oxide film can be reduced, and the surface state, flatness, and thickness precision of the aluminum alloy thick plate can be improved, and productivity can be improved. Further, by heat-treating the aluminum alloy thick plate by heat treatment, the internal stress can be removed and the internal structure can be made uniform.

Therefore, according to the above-described ninth to twelfth inventions, the strength of the aluminum alloy thick plate can be improved. Further, since the ingot is cut to produce an aluminum alloy thick plate, it is not necessary to reduce the thickness by hot rolling as in the prior art, and the work step can be omitted, so that productivity can be improved. Further, it is possible to suppress the unevenness of the surface and the cross section of the thick plate (uneven color tone), and to improve the flatness, the appearance property after the treatment of the aluminum oxide film, and the thickness accuracy. It also improves the balance between flatness, strength and machinability of aluminum alloy thick plates. In other words, since the heat treatment of the ingot at a temperature of not more than 400 ° C (or 350 ° C) of 200 ° C or more can prevent the ductility from becoming high, the machinability (cutting fracture property) is not deteriorated, and the inside can be obtained. Removal of stress and homogenization of internal organization. Therefore, it can be achieved well Flatness and plate thickness accuracy. It can maintain strength.

According to the above configuration (E), the surface state and flatness of the aluminum alloy thick plate can be further improved. Further, by smoothing the surface, the gas accumulation on the surface of the thick plate disappears, and when the aluminum alloy thick plate is applied to the chamber for the vacuum device, the vacuum degree of the chamber can be increased.

According to the above configuration (F), the central portion of the ingot which is likely to be uneven in the surface and the cross section of the aluminum alloy thick plate after the alumite treatment is obtained, and thus it is obtained, and has an excellent appearance after the treatment of the aluminum oxide film. Aluminium alloy thick plate. It can also reduce the staggering situation in the batch.

According to the thirteenth invention, excellent surface condition, flatness, and plate thickness precision can be obtained. Further, by the surface smoothing treatment, the gas accumulation disappears and high quality is obtained. Further, since the surface appearance after the treatment of the aluminum oxide film hardly causes unevenness, it can be applied to various uses, and can be recycled and used for other purposes.

The method for producing an aluminum alloy thick plate and the aluminum alloy thick plate of the present invention will be described in detail with reference to the drawings. Here, the invention of the present application will be described by dividing into (A) first to fourth inventions, (B) fifth to eighth inventions, (C) ninth to twelfth inventions, and (D) thirteenth inventions.

(A) Method for producing aluminum alloy thick plate according to the first to fourth inventions (1) Summary of manufacturing methods

Aluminum alloy thick plates of the first to fourth inventions (hereinafter also referred to as "thickness" The manufacturing method of the plate ") is carried out sequentially as shown in Fig. 1; the melting step (S1), the dehydrogenation step (S2), the filtration step (S3), the casting step (S4), the cutting step (S5), Heat treatment step (S6). Further, if necessary, the surface smoothing treatment step (S7) may be performed after the heat treatment step (S6).

In the present manufacturing method, first, an aluminum alloy thick plate of a raw material is melted in a melting step (S1). Next, hydrogen gas is removed from the molten aluminum alloy by a dehydrogenation step (S2). Next, inclusions such as oxides and non-metals are removed by the filtration step (S3). Next, the aluminum alloy is cast into an ingot at the casting step (S4). Then, the ingot is cut at the cutting step (S5) to form an aluminum alloy thick plate of a predetermined thickness. Then, the aluminum alloy thick plate of a predetermined thickness is heat-treated by the heat treatment step (S6), and then, as needed, the surface smoothing treatment is performed by the surface smoothing treatment step (S7).

(2) Aluminum alloy

In the production methods of the first to fourth inventions, the aluminum alloy as the raw material is a 5000-series Al-Mg alloy, a 3000-series Al-Mn alloy, a 6000-series Al-Mg-Si alloy, and a 7000-series. Al-Zn-Mg alloy. The details are explained below.

(2-1) First invention

A 5000 series Al-Mg alloy was used. The aluminum alloy contains Mg: 1.5% by mass to 12.0% by mass, and contains Si: 0.7% by mass or less, Fe: 0.8% by mass or less, Cu: 0.6% by mass or less, Mn: 1.0% by mass or less, Cr: 0.5% by mass or less, Zn: 0.4% by mass or less, Ti: 0.1% by mass or less, and Zr: 0.3% by mass or less At least one kind, and the remainder is composed of Al and unavoidable impurities.

The reason for limiting the numerical value of each component content will be described below.

[Mg: 1.5% by mass to 12% by mass]

Mg has the effect of increasing the strength of the aluminum alloy. If the Mg content is less than 1.5% by mass, the aforementioned effect is low. On the other hand, when the Mg content exceeds 12% by mass, the castability is remarkably lowered, and the production of the product cannot be performed. Therefore, the Mg content is limited to 1.5% by mass to 12% by mass.

[Si: 0.7% by mass or less]

Si has the effect of increasing the strength of the aluminum alloy. Si is usually mixed into an aluminum alloy as a metal material impurity, and an Al-(Fe)-(Mn)-Si-based intermetallic compound is formed in the ingot together with Mn and Fe in the casting step (S4) or the like. When the Si content exceeds 0.7% by mass, a coarse intermetallic compound is formed in the ingot, and thus the surface appearance after the treatment of the alumina film is likely to be uneven. Therefore, the Si content is limited to 0.7% by mass or less.

[Fe: 0.8% by mass or less]

Fe has an effect of making the crystal grains of the aluminum alloy finer and more stable and improving the strength. Fe is usually mixed into an aluminum alloy as a metal material impurity, and is formed in the ingot together with Mn and Si in a casting step (S4) or the like. Al-Fe-(Mn)-(Si) intermetallic compound. When the Fe content exceeds 0.8% by mass, a coarse intermetallic compound is formed in the ingot, and thus the surface appearance after the treatment of the alumina film is likely to be uneven. Therefore, the Fe content is limited to 0.8% by mass or less.

[Cu: 0.6% by mass or less]

Cu has the effect of increasing the strength of the aluminum alloy. However, in order to secure the strength to be used as a thick plate, a Cu content of 0.6% by mass is sufficient. Therefore, the Cu content is limited to 0.6% by mass or less.

[Mn: 1.0% by mass or less]

The effect of Mn is that the strength can be improved by solid-melting in an aluminum alloy. When the Mn content exceeds 1.0% by mass, a coarse intermetallic compound is formed, so that the surface appearance after the treatment of the aluminum oxide film is likely to be uneven. Therefore, the Mn content is limited to 1.0% by mass or less.

[Cr: 0.5% by mass or less]

The effect of Cr is that in the casting step (S4) and the heat treatment step (S6), precipitation of fine crystals is suppressed to suppress crystal grain growth. When the Cr content exceeds 0.5% by mass, the primary crystal forms a coarse Al—Cr-based intermetallic compound, and thus the surface appearance after the treatment of the aluminum oxide film tends to be uneven. Therefore, the Cr content is limited to 0.5% by mass or less.

[Zn: 0.4% by mass or less]

Zn has the effect of increasing the strength of the aluminum alloy. However, in order to ensure the strength to be used as a thick plate, a Zn content of 0.4% by mass is sufficient. Therefore, the Zn content is limited to 0.4% by mass or less.

[Ti: 0.1% by mass or less]

Ti has an effect of making the crystal grains of the ingot fine. If the Ti content exceeds 0.1% by mass, the aforementioned effect is saturated. Therefore, the Ti content is limited to 0.1% by mass or less.

[Zr: 0.3% by mass or less]

Zr has an effect of making the crystal grains of the ingot fine. If the Zr content exceeds 0.3% by mass, the aforementioned effect is saturated. Therefore, the Zr content is limited to 0.3% by mass or less.

[Al and unavoidable impurities: the remaining part]

The Al alloy is composed of Al and unavoidable impurities in addition to the above components. The unavoidable impurities include, for example, V, B, and the like, and the content of the impurities is not more than 0.01% by mass, and the characteristics of the aluminum alloy thick plate of the present invention are not affected.

(2-2) Second invention

A 3000 series Al-Mn alloy was used. The aluminum alloy contains Mn: 0.3% by mass to 1.6% by mass, and contains Si: 0.7% by mass or less, Fe: 0.8% by mass or less, Cu: 0.5% by mass or less, and Mg: 1.5% by mass. % or less, Cr: 0.3% by mass or less, Zn: 0.4% by mass or less, Ti: 0.1% by mass or less, and Zr: 0.3% by mass or less, and the remainder is composed of Al and unavoidable impurities.

The reason for limiting the numerical value of the content of each component will be described below.

In addition, the reason for the limitation of Si, Fe, Cu, Cr, Zn, Ti, and Zr and the unavoidable impurities are the same as those of the above-described Al-Mg-based alloy, and the description thereof is omitted here.

[Mn: 0.3% by mass to 1.6% by mass]

The effect of Mn is that the strength can be improved by solid-melting in an aluminum alloy. If the Mn content is less than 0.3% by mass, the aforementioned effect is low. When the Mn content exceeds 1.6% by mass, a coarse intermetallic compound is formed, so that the surface appearance after the treatment of the aluminum oxide film is likely to be uneven. Therefore, the Mn content is limited to 0.3% by mass to 1.6% by mass.

[Mg: 1.5% by mass or less]

Mg has the effect of increasing the strength of the aluminum alloy. However, in order to secure the strength to be used as a thick plate, a Mg content of 1.5% by mass is sufficient. Therefore, the Mg content is limited to 1.5% by mass or less.

(2-3) Third invention

A 6000 series Al-Mg-Si alloy was used. The aluminum alloy contains Si: 0.2% by mass to 1.6% by mass, Mg: 0.3% by mass to 1.5% by mass, and contains Fe: 0.8% by mass or less and Cu: 1.0% by mass. Lower, Mn: 0.6% by mass or less, Cr: 0.5% by mass or less, Zn: 0.4% by mass or less, Ti: 0.1% by mass or less, and Zr: 0.3% by mass or less, at least one of which is Al and inevitable Made up of impurities.

The reason for limiting the numerical value of the content of each component will be described below.

In addition, the reason for limiting the Fe, Mn, Cr, Ti, and Zr and the unavoidable impurities are the same as those of the above-described Al-Mg-based alloy, and the description thereof is omitted here.

[Si: 0.2% by mass to 1.6% by mass]

Si has the effect of increasing the strength of the aluminum alloy. Si is usually mixed into an aluminum alloy as a metal material impurity, and an Al-(Fe)-Si-based intermetallic compound and an Si-based intermetallic compound are formed in the ingot in the casting step (S4) or the like. If the Si content is less than 0.2% by mass, the aforementioned effect is low. When the Si content exceeds 1.6% by mass, a coarse Si-based intermetallic compound is formed in the ingot, and thus the surface appearance after the treatment of the alumina film is likely to be uneven. Therefore, the Si content is limited to 0.2% by mass to 1.6% by mass.

[Mg: 0.3% by mass to 1.5% by mass]

The effect of Mg is to form Mg ₂ Si by coexistence with Si to enhance the strength of the aluminum alloy. If the Mg content is less than 0.3% by mass, the aforementioned effect is low. If the Mg content exceeds 1.5% by mass, the aforementioned effect is saturated. Therefore, the Mg content is limited to 0.3% by mass to 1.5% by mass.

[Cu: 1.0% by mass or less]

Cu has the effect of increasing the strength of the aluminum alloy. When the Cu content exceeds 1.0% by mass, the corrosion resistance is deteriorated. Therefore, the Cu content is limited to 1.0% by mass or less.

[Zn: 0.4% by mass or less]

Zn has the effect of increasing the strength of the aluminum alloy. If the Zn content exceeds 0.4% by mass, the corrosion resistance is deteriorated. Therefore, the Zn content is limited to 0.4% by mass or less.

(2-4) Fourth invention

A 7000 series Al-Zn-Mg alloy was used. The aluminum alloy contains Mg: 0.4% by mass to 4.0% by mass, Zn: 3.0% by mass to 9.0% by mass, and contains Si: 0.7% by mass or less, Fe: 0.8% by mass or less, and Cu: 3.0% by mass or less. Mn: 0.8% by mass or less, Cr: 0.5% by mass or less, Ti: 0.1% by mass or less, and Zr: 0.25 mass% or less, at least one of which is Al and an unavoidable impurity.

The reason for limiting the numerical value of the content of each component will be described below.

In addition, the reason for limiting the Cr, Ti, and Zr and the unavoidable impurities are the same as those of the above-described Al-Mg-based alloy, and the description thereof is omitted here.

[Mg: 0.4% by mass to 4.0% by mass]

Mg has the effect of increasing the strength of the aluminum alloy. If the Mg content is less than 0.4% by mass, the aforementioned effect is low. On the other hand, when the Mg content exceeds 4.0% by mass, the surface appearance after the treatment of the aluminum oxide film tends to be uneven. therefore The Mg content is limited to 0.4% by mass to 4.0% by mass.

[Zn: 3.0% by mass to 9.0% by mass]

Zn has the effect of increasing the strength of the aluminum alloy. If the Zn content is less than 3.0% by mass, the aforementioned effect is low. On the other hand, when the Zn content exceeds 9.0% by mass, the surface appearance after the treatment of the aluminum oxide film tends to be uneven. Therefore, the Zn content is limited to 3.0% by mass to 9.0% by mass.

[Si: 0.7% by mass or less]

Si is usually mixed into an aluminum alloy as a metal material impurity, and an Al-(Fe)-Si-based intermetallic compound is formed in the ingot in the casting step (S4) or the like. When the Si content exceeds 0.7% by mass, a coarse Al—(Fe)—Si-based intermetallic compound is formed in the ingot, and thus the surface appearance after the treatment of the aluminum oxide film is likely to be uneven. Therefore, the Si content is limited to 0.7% by mass or less.

[Fe: 0.8% by mass or less]

Fe is usually mixed into the aluminum alloy as a metal material impurity, and an Al-Fe-based intermetallic compound is formed in the ingot in the casting step (S4) or the like. When the Fe content exceeds 0.8% by mass, a coarse Al—Fe-based intermetallic compound is formed in the ingot, and thus the surface appearance after the treatment of the alumina film is likely to be uneven. Therefore, the Fe content is limited to 0.8% by mass or less.

[Cu: 3.0% by mass or less]

Cu has the effect of increasing the strength of the aluminum alloy. When the Cu content exceeds 3.0% by mass, the corrosion resistance is deteriorated. Therefore, the Cu content is limited to 3.0% by mass or less.

[Mn: 0.8% by mass or less]

Mn has an effect of making the crystal structure fine. When the Mn content exceeds 0.8% by mass, a coarse intermetallic compound is formed, so that the surface appearance after the treatment of the aluminum oxide film is likely to be uneven. Therefore, the Mn content is limited to 0.8% by mass or less.

(3) Details of the manufacturing method

Next, each step of the manufacturing method of the first to fourth inventions will be described.

(3-1) Melting step

The melting step (S1) is a step of melting the aluminum alloy of the raw material.

(3-2) Dehydrogenation step

The dehydrogenation step (S2) is a step of removing hydrogen gas from the aluminum alloy melted in the melting step (S1).

Hydrogen is produced from hydrogen in fuel, moisture attached to metal materials, and organic matter. If a large amount of hydrogen is contained, the following problems occur.

[a] A pinhole occurs.

[b] The strength of the product deteriorates.

[c] At the grain boundary near the surface of the ingot, hydrogen accumulation and concentration occur. Therefore, the bulging of the ingot and the rolling up of the aluminum alloy slab which is caused by the bulging occur. This can occur as a potential defect in the surface of the slab that can form surface defects of the slab.

Therefore, in 100 g of the aluminum alloy, the hydrogen content is preferably 0.2 ml or less, more preferably 0.1 ml or less. In order to remove hydrogen, the melt may be subjected to flux treatment, chlorine refining, in-line refining, etc., and more preferably, a suction device or a porous plug may be further used in the dehydrogenation device (refer to Japanese Patent Laid-Open 2002). -14644 bulletin).

The hydrogen concentration of the ingot can be obtained, for example, in the following manner. That is, the sample is cut from the ingot after the casting step. Next, the sample was subjected to ultrasonic cleaning with ethanol and acetone. The sample is then treated with, for example, an inert gas stream melting thermal conductivity method (LIS A06-1993).

The hydrogen concentration of the aluminum alloy thick plate can be obtained, for example, in the following manner. That is, the sample is cut from the aluminum alloy thick plate. Next, the sample was immersed in an aqueous NaOH solution. The nitric acid treatment is then used to remove the oxide film on the surface of the sample. The sample was then washed with ultrasound and ethanol and acetone. Next, the sample is processed, for example, by a vacuum heating extraction capacity method (LIS A06-1993).

(3-3) Filtering step

The filtering step (S3) is a step of removing inclusions (mainly oxides and non-metals) from the aluminum alloy by a filtering device. In the filtration device, for example, a ceramic tube (aluminum using particles of about 1 mm) is provided. By making

The melt is passed through the aforementioned ceramic tube to remove the aforementioned inclusions.

Through the aforementioned dehydrogenation step and filtration step, in the subsequent casting step (S4), the ingot can be obtained from the aluminum alloy ensuring high quality. Since the formation of deposits (scum) of oxides can be suppressed, the operation of removing scum can be reduced.

(3-4) Casting step

In the casting step (S4), the aluminum alloy melt is formed into a predetermined shape such as a square shape to produce an ingot. For example, a casting device having a water-cooled mold is used. The casting method is a semi-continuous casting method. In the semi-continuous casting method, a metal water-cooling mold opened to the bottom is injected with a molten aluminum alloy from above, and the solidified aluminum alloy is continuously taken out from the bottom of the water-cooled mold. Thereby, an ingot of a predetermined thickness is obtained. The semi-continuous casting method can be carried out in a longitudinal or transverse manner.

(3-5) Cutting step

The cutting step (S5) is a step of cutting the ingot obtained by the casting step (S4) into an aluminum alloy thick plate of a predetermined thickness. Regarding the cutting method, a slab cutting method can be employed. In the thick plate cutting method, the ingot obtained by the above-described semi-continuous casting method is cut in a casting direction by a band saw cutter or the like to obtain an aluminum alloy thick plate having a predetermined thickness. The aluminum alloy thick plate is preferably 15 to 200 mm, but is not particularly limited and can be appropriately adjusted depending on the use of the thick plate.

As a cutting method, it is better to use a band saw, but there is no special limit. It is also possible to use circular saws, lasers, water pressure, etc.

In the case of rolling, if the ingot is cut, an aluminum alloy thick plate excellent in surface condition, flatness, and thickness accuracy can be obtained. For example, an aluminum alloy thick plate having a flatness (bending amount) of 0.4 mm or less, a casting direction of 1 m long, and a plate thickness accuracy of ±100 μm or less can be obtained.

Further, as shown in Fig. 2, in the cutting step (S5), it is preferable to remove the central portion B of the oblique line. The central portion B has a uniform thickness from the center A in the thickness direction toward the surface in the thickness direction, and the thickness of the ingot 1 is T, and has a total thickness of T/30 to T/5. In Fig. 2, the central portion B has a thickness of about T/5. Here, the lower thicknesses b1 and b2 above the central portion B of the ingot 1 are preferably the same, but allow a difference of about 30%. The center A in the thickness direction refers to a portion in the thickness direction of the ingot 1 and a thickness T of the ingot 1 of about 1/2, that is, a portion of about T/2.

In the central portion B of the ingot 1, the surface and the cross section of the slab after the treatment of the alumina film are likely to be uneven. In the dicing step (S5), by removing the central portion B, a thick plate excellent in appearance after the treatment of the aluminum oxide film can be obtained. It can also reduce the staggering situation in the batch. On the other hand, if the thickness to be removed is less than T/30, it is likely that the surface appearance after the treatment of the aluminum oxide film has uneven thick plates, and the unevenness in the batch is likely to occur. On the other hand, if the thickness to be removed exceeds T/5, the amount of removal becomes excessive, which may cause deterioration in productivity. Therefore, the removal amount of the central portion B of the ingot 1 is preferably limited to have a uniform thickness from the center A in the thickness direction toward the thickness direction, and the thickness of the ingot 1 is T, and the total has T/30. ~T/5 thickness.

After the ingot is cut through the cutting step (S5), heat treatment is performed in the subsequent heat treatment step (S6) in order to remove the internal stress and uniformize the internal structure. By performing the heat treatment, the flatness, the thickness accuracy, and the appearance characteristics after the aluminum oxide film treatment can be improved.

(3-6) Heat treatment step

The heat treatment step (S6) is a step of subjecting the aluminum alloy thick plate of a predetermined thickness obtained by the cutting step (S5) to a heat treatment (homogenization heat treatment). The heat treatment can be carried out in accordance with a usual method. In other words, the aluminum alloy is a 5000-series Al-Mg-based alloy (first invention), a 3000-series Al-Mn alloy (second invention), and a 6000-series Al-Mg-Si alloy (third invention). In this case, the heat treatment is carried out by maintaining the temperature at 400 ° C or higher and not reaching the melting point for 1 hour or more. Further, in the case where the aluminum alloy is a 7000-series Al-Zn-Mg-based alloy (the fourth invention), the heat treatment is carried out by maintaining the temperature at 350 ° C or higher for less than 1 hour.

If the ingot obtained by the casting step (S4) is subjected to a cutting process, the internal residual stress is released and the bending is likely to occur. However, in the present invention, since the heat treatment is performed by placing the aluminum alloy thick plate of a predetermined thickness after the cutting process, for example, on a fixed plate or the like, the flatness can be improved.

In the first to third inventions, when the treatment temperature is less than 400 ° C, the amount of removal of the internal stress is small, and the homogenization of the molten element segregated during casting is insufficient, so that the effect of the heat treatment is low. The treatment temperature is then limited to 400 ° C or higher. Further, if the treatment temperature is higher than the melting point, local melting occurs inside to cause internal defects, and strength and ductility are deteriorated. Therefore will handle the temperature The degree is limited to not reach the melting point.

According to the fourth aspect of the invention, when the treatment temperature is less than 350 ° C, the amount of removal of the internal stress is small, and the homogenization of the molten element segregated during casting is insufficient, so that the effect of the heat treatment is low. The treatment temperature is then limited to 350 ° C or higher. Further, if the treatment temperature is higher than the melting point, local melting occurs inside to cause internal defects, and strength and ductility are deteriorated. Therefore, the treatment temperature is limited to not reach the melting point.

If the treatment time is less than 1 hour, the degree of solid solution of the intermetallic compound is insufficient, and the intermetallic compound is easily precipitated. Therefore, the treatment time is limited to 1 hour or more. If the treatment time exceeds 8 hours, the effect of the heat treatment is saturated, which will cause energy loss. Therefore, the treatment time should be limited to 8 hours or less.

The aluminum alloy thick plate after the heat treatment in the heat treatment step (S6) may be subjected to surface smoothing treatment in order to remove crystal grains and oxides formed on the surface of the thick plate or to suppress gas deposition on the surface of the thick plate.

(3-7) Surface smoothing processing steps

The surface smoothing treatment step (S7) is a step of performing surface smoothing treatment on the surface of the aluminum alloy thick plate obtained by the heat treatment step (S6). As the surface smoothing treatment method, a cutting method such as end milling or diamond turning, a grinding method in which a surface is ground with a grindstone, a grinding method such as polishing, or the like can be employed; however, it is not limited thereto.

When the aluminum alloy thick plate is applied to the chamber for a vacuum apparatus, it is particularly effective to carry out the surface smoothing treatment. The reason is as follows. That is, vacuum loading When the pressure in the chamber is lowered to a high vacuum, the adsorbed gas discharged from the indoor side surface or the gas atoms which are solidified in the thick plate are released toward the surface, which causes the degree of vacuum to deteriorate. Therefore, the time to reach the target vacuum degree becomes long, and the production efficiency deteriorates. Based on this, the aluminum alloy thick plate applied to the chamber must require that the gas adsorbed on the surface of the thick plate (on the indoor side) is small, and even if a high vacuum is formed, gas atoms solidified in the thick plate are not released.

(B) Method for producing aluminum alloy thick plate according to the fifth to eighth inventions (1) Summary of manufacturing methods

The method for producing the aluminum alloy thick plate according to the fifth to eighth inventions is carried out in sequence as shown in Fig. 3: a melting step (S1), a dehydrogenation step (S2), a filtration step (S3), and a casting step (S4). ), a heat treatment step (S5), and a cutting step (S6). Further, a surface smoothing treatment step (S7) may be performed after the cutting step (S6) as needed.

In the present manufacturing method, first, an aluminum alloy thick plate of a raw material is melted in a melting step (S1). Next, hydrogen gas is removed from the molten aluminum alloy by a dehydrogenation step (S2). Next, inclusions such as oxides and non-metals are removed by the filtration step (S3). Next, the aluminum alloy is cast into an ingot at the casting step (S4). Then, the ingot is subjected to heat treatment in the heat treatment step (S5), and then cut in the cutting step (S5) to form an aluminum alloy thick plate having a predetermined thickness. Next, the surface smoothing treatment is performed by the surface smoothing treatment step (S7) as needed for the aluminum alloy thick plate having a predetermined thickness.

(2) Aluminum alloy

In the production methods of the fifth to eighth inventions, the aluminum alloy as the raw material is a 5000-series Al-Mg alloy, a 3000-series Al-Mn alloy, a 6000-series Al-Mg-Si alloy, and a 7000-series. Al-Zn-Mg alloy. The details are explained below.

(2-1) Fifth invention

The 5000-series Al-Mg alloy similar to the first invention was used. The reason why the numerical value of the composition, component content, and content of the aluminum alloy is limited is the same as that of the first invention.

(2-2) Sixth invention

The 3000-series Al-Mn alloy similar to the second invention was used. The reason why the numerical value of the composition, component content, and content of the aluminum alloy is limited is the same as that of the second invention.

(2-3) Seventh invention

The 6000-based Al-Mg-Si alloy similar to the third invention was used. The reason why the numerical value of the composition, component content, and content of the aluminum alloy is limited is the same as that of the third invention.

(2-4) Eighth invention

The same 7000 series Al-Zn-Mg alloy as in the fourth invention was used. The reason for the limitation of the composition, component content, and content of the aluminum alloy is The fourth invention is the same.

(3) Details of the manufacturing method

Next, each step of the manufacturing method of the fifth to eighth inventions will be described in detail.

(3-1) Melting step

It is the same as the melting step (S1) of the first to fourth inventions.

(3-2) Dehydrogenation step

It is the same as the dehydrogenation step (S2) of the first to fourth inventions.

(3-3) Filtering step

It is the same as the filtration step (S3) of the first to fourth inventions.

(3-4) Casting step

It is the same as the casting step (S4) of the first to fourth inventions.

After the ingot obtained by the casting step (S4) is cut, in the subsequent heat treatment step (S5), heat treatment is performed for the purpose of removing internal stress and homogenizing the internal structure. By performing heat treatment on the ingot, the flatness, the thickness accuracy, and the appearance property after the aluminum oxide film treatment can be improved.

(3-5) Heat treatment step

The heat treatment step (S5) is a casting obtained by the casting step (S4) The block is subjected to a heat treatment (homogenization heat treatment) step. The heat treatment can be carried out in accordance with a usual method. In other words, the aluminum alloy is a 5000-series Al-Mg-based alloy (the fifth invention), a 3000-series Al-Mn alloy (the sixth invention), and a 6000-based Al-Mg-Si alloy (the seventh invention). In this case, the heat treatment is performed by maintaining the temperature at 200 ° C or more and less than 400 ° C for 1 hour or more. Further, in the case where the aluminum alloy is a 7000-series Al-Zn-Mg-based alloy (the eighth invention), the heat treatment is performed by maintaining the temperature at 200 ° C or more and less than 300 ° C for 1 hour or more.

In the fifth to seventh inventions, when the treatment temperature is less than 200 ° C, the amount of removal of the internal stress is small, and the effect of performing the heat treatment is low. Therefore, the treatment temperature is limited to 200 ° C or more. Further, if the treatment temperature is 400 ° C or more, the ductility becomes high, and the strength and the machinability are deteriorated. Machinability represents chip breaking. The chips are preferably broken into small pieces. The reason is that if the chips are long, they will be wound around the processing tool (knife) and rotate together, which will cause the surface of the thick plate to be damaged and the tool to be damaged. Therefore, the treatment temperature is limited to less than 400 °C. By performing heat treatment under such temperature conditions, strength and machinability are not reduced, and flatness and thickness accuracy can be improved.

According to the eighth aspect of the invention, when the treatment temperature is less than 200 ° C, the amount of removal of the internal stress is small, and the effect of performing the heat treatment is low. Therefore, the treatment temperature is limited to 200 ° C or more. Further, if the treatment temperature is 350 ° C or more, the ductility becomes high, and the strength and the machinability are deteriorated. Machinability represents chip breaking. The chips are preferably broken into small pieces. The reason is that if the chips are long, they will be wound around the processing tool (knife) and rotate together, which will cause the surface of the thick plate to be damaged and the tool to be damaged. Therefore, the treatment temperature is limited to less than 350 °C. By using this temperature Conditions for heat treatment without reducing strength and machinability, and improving flatness and plate thickness accuracy.

If the treatment time is less than 1 hour, the degree of solid solution of the intermetallic compound is insufficient, and the intermetallic compound is easily precipitated. Therefore, the treatment time is limited to 1 hour or more. If the treatment time exceeds 8 hours, the effect of the heat treatment is saturated, which will cause energy loss. Therefore, the treatment time should be limited to 8 hours or less.

(3-6) Cutting step

The cutting step (S6) is a step of cutting the ingot obtained in the heat treatment step (S5) into an aluminum alloy thick plate of a predetermined thickness. The details are the same as the cutting steps (S5) of the first to fourth inventions.

The aluminum alloy thick plate after the cutting step (S6) may be subjected to surface smoothing treatment in order to remove crystals and oxides formed on the surface of the thick plate or to suppress gas deposition on the surface of the thick plate.

(3-7) Surface smoothing processing steps

The surface smoothing treatment step (S7) is a step of subjecting the surface of the aluminum alloy thick plate obtained in the cutting step (S6) to a surface smoothing treatment. The details are the same as those of the surface smoothing processing step (S7) of the first to fourth inventions.

(C) Method for producing aluminum alloy thick plate according to the ninth to twelfth inventions (1) Summary of manufacturing method

The method for producing an aluminum alloy thick plate (hereinafter also referred to as "thick plate") according to the ninth to twelfth aspects of the present invention is sequentially performed as shown in Fig. 1 : a melting step (S1), a dehydrogenation step (S2), The filtration step (S3), the casting step (S4), the cutting step (S5), and the heat treatment step (S6). Further, if necessary, the surface smoothing treatment step (S7) may be performed after the heat treatment step (S6).

In the present manufacturing method, first, an aluminum alloy thick plate of a raw material is melted in a melting step (S1). Next, hydrogen gas is removed from the molten aluminum alloy by a dehydrogenation step (S2). Next, inclusions such as oxides and non-metals are removed by the filtration step (S3). Next, the aluminum alloy is cast into an ingot at the casting step (S4). Then, the ingot is cut at the cutting step (S5) to form an aluminum alloy thick plate of a predetermined thickness. Then, the aluminum alloy thick plate of a predetermined thickness is heat-treated by the heat treatment step (S6), and then, as needed, the surface smoothing treatment is performed by the surface smoothing treatment step (S7).

(2) Aluminum alloy

In the manufacturing method of the ninth to twelfth aspects of the invention, the aluminum alloy as the raw material is a 5000-series Al-Mg alloy, a 3000-series Al-Mn alloy, a 6000-series Al-Mg-Si alloy, and a 7000-series. Al-Zn-Mg alloy. The details are explained below.

(2-l) ninth invention

The 5000-series Al-Mg alloy similar to the first invention was used. The aluminum The reason why the numerical value of the composition, component content, and content of the alloy is limited is the same as that of the first invention.

(2-2) The tenth invention

The 3000-series Al-Mn alloy similar to the second invention was used. The reason why the numerical value of the composition, component content, and content of the aluminum alloy is limited is the same as that of the second invention.

(2-3) Eleventh invention

The 6000-based Al-Mg-Si alloy similar to the third invention was used. The reason why the numerical value of the composition, component content, and content of the aluminum alloy is limited is the same as that of the third invention.

(2-4) The twelfth invention

The same 7000 series Al-Zn-Mg alloy as in the fourth invention was used. The reason why the numerical value of the composition, component content, and content of the aluminum alloy is limited is the same as that of the fourth invention.

(3) Details of the manufacturing method

Next, each step of the manufacturing method of the ninth to twelfth inventions will be described in detail.

(3-1) Melting step

It is the same as the melting step (S1) of the first to fourth inventions.

(3-2) Dehydrogenation step

It is the same as the dehydrogenation step (S2) of the first to fourth inventions.

(3-3) Filtering step

It is the same as the filtration step (S3) of the first to fourth inventions.

(3-4) Casting step

It is the same as the casting step (S4) of the first to fourth inventions.

(3-5) Cutting step

It is the same as the cutting step (S5) of the first to fourth inventions.

(3-6) Heat treatment step

The heat treatment step (S6) is a step of subjecting the aluminum alloy thick plate of a predetermined thickness obtained by the cutting step (S5) to a heat treatment (homogenization heat treatment). The heat treatment can be carried out in accordance with a usual method. In other words, the aluminum alloy is a 5000-series Al-Mg alloy (ninth invention), a 3000-series Al-Mn alloy (tenth invention), and a 6000-series Al-Mg-Si alloy (11th invention). In the case, the heat treatment is carried out by maintaining the temperature at 200 ° C or more and less than 400 ° C for 1 hour or more. Further, in the case where the aluminum alloy is a 7000-series Al-Zn-Mg-based alloy (12th invention), the heat treatment is carried out by maintaining the temperature at 200 ° C or higher and less than 350 ° C for 1 hour or longer.

In the ninth to eleventh inventions, if the treatment temperature is less than 200 ° C, the internal should The amount of force removal is small, and the effect of performing heat treatment is low. Therefore, the treatment temperature is limited to 200 ° C or more. Further, if the treatment temperature is 400 ° C or more, the ductility becomes high, and the strength and the machinability deteriorate. Machinability represents chip breaking. The chips are preferably broken into small pieces. The reason is that if the chips are long, they will be wound around the processing tool (knife) and rotate together, which will cause the surface of the thick plate to be damaged and the tool to be damaged. Therefore, the treatment temperature is limited to less than 400 °C. By performing heat treatment under such temperature conditions, strength and machinability are not reduced, and flatness and thickness accuracy can be improved.

According to the twelfth aspect of the invention, when the treatment temperature is less than 200 °C, the amount of removal of the internal stress is small, and the effect of performing the heat treatment is low. Therefore, the treatment temperature is limited to 200 ° C or more. Further, if the treatment temperature is 350 ° C or more, the ductility becomes high, and the strength and the machinability deteriorate. Machinability represents chip breaking. The chips are preferably broken into small pieces. The reason is that if the chips are long, they will be wound around the processing tool (knife) and rotate together, which will cause the surface of the thick plate to be damaged and the tool to be damaged. Therefore, the treatment temperature is limited to less than 350 °C. By performing heat treatment under such temperature conditions, strength and machinability are not reduced, and flatness and thickness accuracy can be improved.

If the treatment time is less than 1 hour, the degree of solid solution of the intermetallic compound is insufficient, and the intermetallic compound is easily precipitated. Therefore, the treatment time is limited to 1 hour or more. If the treatment time exceeds 8 hours, the effect of the heat treatment is saturated, which will cause energy loss. Therefore, the treatment time should be limited to 8 hours or less.

(3-7) Surface smoothing processing steps

It is the same as the surface smoothing processing step (S7) of the first to fourth inventions.

(D) Invention 13

Next, the aluminum alloy thick plate of the present invention will be described.

The aluminum alloy thick plate is produced by the method for producing an aluminum alloy thick plate according to any one of the first to twelfth aspects of the invention, and has an average crystal grain size of 400 μm or less.

According to the aluminum alloy thick plate of the present invention, since the average crystal grain size is 400 μm or less, the appearance of the aluminum oxide film after treatment can be improved, and the variation in the batch can be reduced.

When the size of the intermetallic compound of the thick plate is increased, unevenness (tone unevenness) occurs in the cross section and the surface of the thick plate when the aluminum oxide film is treated. However, according to the aluminum alloy thick plate of the present invention, since the size of the intermetallic compound is small, unevenness does not easily occur.

The measurement of the crystal grain size described above is carried out, for example, in the following manner. In other words, the thickness of the ingot is T, and the measured value is obtained from the surface of one surface of the ingot toward the other surface at four thicknesses of T/5, 2T/5, 3T/5, and 4T/5. Its average. Such a method of obtaining a measured value can be, for example, a cutting method. In the cutting method, the cross section of the aluminum alloy thick plate was etched by a peeling method, and then observed with an optical microscope.

Regarding the method of controlling the average crystal grain size to 400 μm or less, for example, the following method can be employed. That is, the cooling rate at the time of casting (the average temperature from the liquidus temperature to the solidus temperature) is set to 0.2 ° C /sec or more. In the case of the production methods of the first to third inventions, the fifth to seventh inventions, and the ninth to eleventh aspects of the invention, it is possible to make the aluminum alloy contain 0.1% by mass or less of Ti or 0.3% by mass or less of Zr. In the case where the aluminum alloy contains 0.1% by mass or less of Ti or 0.25 mass% or less of Zr, the aluminum alloy can be made to have a finer crystal grain size, and in the case of the production method of the fourth invention, the eighth invention, and the twelfth invention. The crystal grain size is more fine.

As described above, the aluminum alloy thick plate obtained by the above-described first to twelfth inventions is excellent in surface condition, flatness, and plate thickness accuracy, and can be applied to various applications (including a base substrate and a conveying device). Semiconductor related devices such as vacuum chambers; motor electronic components and their manufacturing devices; household goods; mechanical parts, etc., can also be recycled for other uses.

Further, the corrosion resistance of the aluminum alloy thick plate does not pose a problem. The reason for this is that the thick plate for the base substrate and the thick plate for the transfer device do not generally have to be considered for corrosion resistance because they are applied to the clean room. Also applied to thick plates for vacuum chambers, since it is used in an environment exposed to less corrosive gases, it is not necessary to consider strict corrosion resistance.

The above is a description of the preferred embodiments of the present invention, but the present invention is not limited to the embodiments described above.

Example

Embodiments of the invention of the present application are described below.

(1) First Embodiment

This embodiment relates to the first invention. The aluminum alloy used in the present embodiment is a 5000-series Al-Mg-based alloy.

Alloys 1A to 12A shown in Table 1 were used as the alloys of the examples, and alloys 13A to 22A were used as the alloys of the comparative examples.

(deal with)

First, the alloys 1A to 22A were sequentially subjected to a melting step, a dehydrogenation step, a filtration step, and a casting step to prepare an ingot having a thickness of 500 mm.

Next, a cut material and a hot rolled material were produced from the above ingot. The cutting material is obtained by processing the aforementioned ingot through a cutting step. The hot rolled material is obtained by heat-treating the ingot and then hot rolling. The cutting material and the hot rolled material are aluminum alloy thick plates with a thickness of 20 mm × a width of 1000 mm × a length of 2000 mm.

Next, the above-mentioned cutting material is treated with a heat treatment step. That is, the aforementioned cutting material was kept at 500 ° C for 4 hours.

Therefore, the cut material after the above treatment is the aluminum alloy thick plate obtained by the production method of the first invention, but the hot rolled material after the above treatment is not. Only the cutting materials using the alloys 1A to 22A are examples belonging to the first invention.

Next, the following test was performed on the cut material and the hot rolled material after the above treatment.

<flatness evaluation test>

The flatness evaluation is a bending amount (flatness) per 1 m in the casting direction for the cutting material, and a bending amount (flatness) per 1 m in the rolling direction for the hot rolled material. When the flatness is 0.4 mm/1 m or less, it is judged as pass (○), and when it exceeds 0.4 mm/l m, it is judged as unacceptable (×).

<Plate thickness accuracy test>

The thickness accuracy evaluation was performed by measuring the thickness of six parts with a micrometer. The six parts include: 4 turns of the thick plate, and a portion from the half length of the long side of the thick plate toward the inner side of the width direction of 20 mm. When all of the six parts were judged to be good (?) in the case of 19.94 mm to 20.06 mm, they were judged to be acceptable (○) in the case of 19.90 mm to 20.10 mm.

<strength test>

The strength test was carried out in the following manner. That is, a test piece of JIS No. 5 was produced from an aluminum alloy thick plate, and a tensile test was performed using the test piece, and tensile strength and 0.2% safety limit stress were measured. When the tensile strength was 180 N/mm ² or more, it was judged as pass (○), and when the tensile strength was less than 180 N/mm ² , it was judged as unacceptable (×).

<Alumina film treatment evaluation test>

The evaluation of the handleability of the aluminum oxide film was carried out in the following manner. On the surface and cross section of the aluminum alloy thick plate, an alumina film having a thickness of 10 μm was formed by treatment with an alumina sulfate film. The treatment conditions were 15% sulfuric acid, 20 ° C, and current density 2 A/dm ² . Observe the appearance of the surface and section of the slab. The case where the appearance was not uneven (hue unevenness) was judged as pass (○), and the case where unevenness occurred was judged as unacceptable (×).

Since the crystal grain size of the thick plate affects the handleability of the aluminum oxide film, the average crystal grain size of the thick plate is determined. The average crystal grain size is determined by the following To proceed. That is, the thickness of the aluminum alloy thick plate is T, and the measured value is obtained from the cross section of one surface of the thick plate toward the other surface at four thicknesses of T/5, 2T/5, 3T/5, and 4T/5. And find the average. Such a method of obtaining a measured value can be, for example, a cutting method. In the cutting method, the cross section of the aluminum alloy thick plate was etched by a peeling method, and then observed with an optical microscope.

The test results are shown in Tables 2 and 3.

Table 2 shows the test results of the cut material. In Table 2, the alloys 1A to 12A belong to the examples, and the alloys 13A to 22A belong to the comparative example. Table 3 shows the test results of the hot rolled product. In Table 3, all of the alloys 1A to 22A belong to the comparative example.

(about cutting materials)

As shown in Table 2, in the case of the alloys 1A to 13A and the alloys 15A to 22A, the processing strain was small and the bending was small. That is, the flatness is good. The plate thickness is also accurate.

In the case of the alloy 14A, since the Mg content exceeds the upper limit value, casting cracks occur and manufacturing cannot be performed. In the case of the alloy 13A, since the Mg content does not reach the lower limit value, the strength is insufficient.

In the case of the alloys 1A to 13A, 17A, and 20A to 22A, the surface appearance after the treatment of the aluminum oxide film did not occur unevenly. In the case of each of the alloys 15A, 16A, 18A, and 19A, since the contents of Si, Fe, Mn, and Cr exceed the upper limit, respectively, a coarse intermetallic compound is formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloys 1A to 13A and 15A to 22A, the surface appearance after the treatment of the aluminum oxide film did not occur unevenly.

Further, in the case of each of the alloys 17A, 20A, 21A, and 22A, since the contents of Cu, Zn, Ti, and Zr each exceed the upper limit value, the effects thereof are saturated, and the economy is not good.

(About hot rolled steel)

As shown in Table 3, in the case of alloys 1A to 13A and 15A to 22A, The machining strain is accumulated and the bending in the rolling direction is large. That is, the flatness is not good. The plate thickness accuracy is almost inferior to that of the cutting material.

In the case of the alloy 14A, since the Mg content exceeds the upper limit value, casting cracks occur and manufacturing cannot be performed. In the case of the alloy 13A, since the Mg content does not reach the lower limit value, the strength is insufficient.

In the case of each of the alloys 15A, 16A, 18A, and 19A, since the contents of Si, Fe, Mn, and Cr exceed the upper limit, respectively, a coarse intermetallic compound is formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloys 1A to 13A and 15A to 22A, the surface appearance after the treatment of the aluminum oxide film was uneven.

(2) Second embodiment

This embodiment relates to the first invention. In the present embodiment, the alloy 3A shown in Table 1 was used.

(deal with)

First, the alloy 3A was sequentially subjected to a melting step, a dehydrogenation step, a filtration step, and a casting step to prepare an ingot having a thickness of 500 mm.

Next, the ingot is obtained by the treatment of the cutting step to obtain a cut material. The cutting material is an aluminum alloy thick plate having a thickness of 20 mm × a width of 1000 mm × a length of 2000 mm.

Next, the aforementioned cutting material is treated by a heat treatment step. That is, the above-mentioned cutting material was heat-treated under the conditions shown in Table 4.

Therefore, the heat treatment conditions are in accordance with the first invention A1 and A2, and are examples according to the first invention; the heat treatment conditions are not in accordance with A3 to A5 of the first invention, and are comparative examples.

For the cut material after the above treatment, a flatness evaluation test and a thickness evaluation test were performed.

<flatness evaluation test>

The flatness evaluation was performed by measuring the amount of bending (flatness) per 1 m in the casting direction, and the flatness was 0.4 mm/lm or less, and it was judged as acceptable (○), and it was judged to be good when it was 0.25 mm/lm or less ( ◎).

<Plate thickness accuracy test>

The plate thickness accuracy evaluation test is the same as in the case of the first embodiment.

The test results are shown in Table 4.

As shown in Table 4, the heat treatment conditions of Examples A1 and A2 were in accordance with the first According to the invention, the flatness and the plate thickness are excellent. Further, in Comparative Example A3, since the heat treatment was not performed, the flatness and the sheet thickness accuracy were slightly inferior to those of Examples A1 and A2. In Comparative Example A4, since the treatment temperature was lower than the range of the first invention (less than 400 ° C), the flatness was slightly inferior to those of Examples A1 and A2. Further, in Comparative Example A5, since the treatment temperature was higher than the range of the first invention (exceeding the melting point), local melting occurred inside and internal defects were formed, so that the product could not be obtained.

(3) Third embodiment

This embodiment relates to the second invention. The aluminum alloy used in this embodiment is a 3000-series Al-Mn alloy.

Alloys 23A and 24A shown in Table 5 were used as the alloys of the examples, and alloys 25A and 26A were used as the alloys of the comparative examples.

(deal with)

First, the alloys 23A to 26A were sequentially subjected to a melting step, a dehydrogenation step, a filtration step, and a casting step to prepare an ingot having a thickness of 500 mm.

Next, a cut material and a hot rolled material were produced from the above ingot. The cutting material is obtained by treating the aforementioned ingot through a cutting step. The hot rolled material is obtained by heat-treating the ingot and then hot rolling. Both the cutting material and the hot rolled material are aluminum alloy thick plates with a thickness of 20 mm × a width of 1000 mm × a length of 2000 mm.

Next, the aforementioned cutting material is treated by a heat treatment step. That is, the aforementioned cutting material was kept at 500 ° C for 4 hours.

Therefore, the cut material after the above treatment is an aluminum alloy thick plate obtained by the manufacturing method of the second invention, and the hot rolled material after the above treatment is not. Further, only the cutting materials using the alloys 23A and 24A belong to the embodiment of the second invention.

Next, the flatness evaluation test, the thickness evaluation test, the strength test, and the aluminum oxide film treatability evaluation test were performed about the said cutting material and the hot-rolled material.

The method and evaluation criteria of each test are the same as in the case of the first embodiment.

Since the characteristics of the thick plate vary depending on the type of the alloy, the evaluation criteria of the strength are as follows. In other words, in the case of strength, the case where the tensile strength was 90 N/mm ² or more was judged as pass (○), and the case where the tensile strength was less than 90 N/mm ² was judged as unacceptable (×).

The test results are shown in Table 6.

(about cutting materials)

As shown in Table 6, in the case of the alloys 23A to 26A, the processing strain was small and the bending was small. That is, the flatness is good, and the plate thickness precision is excellent.

In the case of Alloy 25A, since the Mn content does not reach the lower limit value, the strength is insufficient. In the case of the alloy 26A, since the Mn content exceeds the upper limit value, a coarse intermetallic compound is formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloys 23A to 26A, the cross-sectional appearance after the treatment of the aluminum oxide film did not cause unevenness.

(About hot rolled steel)

As shown in Table 6, in the case of the alloys 23A to 26A, the machining strain was accumulated, and the bending in the rolling direction was large. That is, the flatness is not good. The plate thickness accuracy is almost inferior to that of the cutting material.

In the case of Alloy 25A, since the Mn content does not reach the lower limit value, the strength is slightly inferior to that of other hot rolled materials. In the case of the alloy 26A, since the Mn content exceeds the upper limit value, a coarse intermetallic compound is formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloys 23A to 26A, the cross-sectional appearance of the aluminum oxide film after treatment was uneven.

(4) Fourth embodiment

This embodiment relates to the third invention. The aluminum alloy used in this embodiment is a 6000 series Al-Mg-Si alloy.

Alloys 27A and 28A shown in Table 7 were used as the alloys of the examples, and alloys 29A to 32A were used as the alloys of the comparative examples.

(deal with)

First, the alloys 27A to 32A were sequentially subjected to a melting step, a dehydrogenation step, a filtration step, and a casting step to prepare an ingot having a thickness of 500 mm.

Next, a cut material and a hot rolled material were produced from the above ingot. The cutting material is obtained by treating the aforementioned ingot through a cutting step. The hot rolled material is obtained by heat-treating the ingot and then hot rolling. Both the cutting material and the hot rolled material are aluminum alloy thick plates with a thickness of 20 mm × a width of 1000 mm × a length of 2000 mm.

Next, the aforementioned cutting material is treated by a heat treatment step. That is, the aforementioned cutting material was kept at 500 ° C for 4 hours.

Further, the obtained cut material and hot rolled material were melted at 520 ° C, and then aged at 175 ° C for 8 hours.

Therefore, the cut material after the above treatment is an aluminum alloy thick plate obtained by the manufacturing method of the third invention, and the hot rolled material after the above treatment is not. Further, only the cutting materials using the alloys 27A and 28A belong to the embodiment of the third invention.

Next, the strength test and the alumina film treatability evaluation test were performed on the cut material and the hot rolled material after the above treatment.

The method and evaluation criteria of each test are the same as in the case of the first embodiment.

Since the characteristics of the thick plate vary depending on the type of the alloy, the evaluation criteria of the strength are as follows. In other words, in the case of the strength, the case where the tensile strength is 200 N/mm ² or more is judged as pass (○), and the case where the tensile strength is less than 200 N/mm′ is judged as unacceptable (×).

The test results are shown in Table 8.

(about cutting materials)

As shown in Table 8, in the case of the alloys 29A and 31A, since the Si and Mg contents were each less than the lower limit, the strength was insufficient. In the case of the alloy 30A, since the Si content exceeds the upper limit value, a coarse intermetallic compound is formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloy 32A, since the Mg content exceeds the upper limit value, the Mg effect is saturated and the economy is poor. In the case of the alloys 27A to 32A, the cross-sectional appearance after the treatment of the aluminum oxide film did not cause unevenness.

(About hot rolled steel)

As shown in Table 8, in the case of the alloys 29A and 31A, since the Si and Mg contents were each less than the lower limit, the strength was insufficient. In the case of the alloy 30A, since the Si content exceeds the upper limit value, a coarse intermetallic compound is formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloy 32A, since the Mg content exceeds the upper limit value, the Mg effect is saturated and the economy is poor. In the case of the alloys 27A to 32A, the cross-sectional appearance after the treatment of the aluminum oxide film may be uneven.

(5) Fifth embodiment

This embodiment relates to the fourth invention. The aluminum alloy used in the present embodiment is a 7000-series Al-Zn-Mg-based alloy.

Alloys 33A and 34A shown in Table 9 were used as the alloys of the examples, and alloys 35A to 38A were used as the alloys of the comparative examples.

(deal with)

First, the alloys 33A to 38A were sequentially subjected to a melting step, a dehydrogenation step, a filtration step, and a casting step to produce an ingot having a thickness of 500 mm.

Next, a cut material and a hot rolled material were produced from the above ingot. The cutting material is obtained by treating the aforementioned ingot through a cutting step. The hot rolled material is obtained by heat-treating the ingot and then hot rolling. Both the cutting material and the hot rolled material are aluminum alloy thick plates with a thickness of 20 mm × a width of 1000 mm × a length of 2000 mm.

Next, the cutting material is processed by a heat treatment step. That is, the aforementioned cutting material was kept at 500 ° C for 4 hours.

Further, the obtained cut material and hot rolled material were melted at 470 ° C, and then subjected to aging treatment at 120 ° C for 48 hours.

Therefore, the cut material after the above treatment is an aluminum alloy thick plate obtained by the manufacturing method of the fourth invention, and the hot rolled material after the above treatment is not. Further, only the cutting material using the alloys 33A and 34A belongs to the embodiment of the fourth invention.

Next, the cut material and the hot rolled material after the treatment are strengthened. The degree test and the evaluation test of the alumina film treatment property.

The method and evaluation criteria of each test are the same as in the case of the first embodiment.

Since the characteristics of the thick plate vary depending on the type of the alloy, the evaluation criteria of the strength are as follows. In other words, in the case of the strength, the case where the tensile strength was 250 N/mm ² or more was judged as pass (○), and the case where the tensile strength was less than 250 N/mm ² was judged as unacceptable (×).

The test results are shown in Table 10.

(about cutting materials)

As shown in Table 10, in the case of the alloys 35A and 37A, since the contents of Mg and Zn were not below the lower limit, the strength was insufficient. In alloys 36A, 38A In other cases, since the Mg and Zn contents respectively exceed the upper limit value, the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloys 33A to 38A, the cross-sectional appearance after the treatment of the aluminum oxide film did not cause unevenness.

(About hot rolled steel)

As shown in Table 10, in the case of the alloys 35A and 37A, since the contents of Mg and Zn were not below the lower limit, the strength was insufficient. In the case of the alloys 36A and 38A, since the Mg and Zn contents respectively exceed the upper limit value, the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloys 33A to 38A, the cross-sectional appearance after the treatment of the aluminum oxide film may be uneven.

(6) Sixth Embodiment

This embodiment relates to the fifth invention. The aluminum alloy used in the present embodiment is a 5000-series Al-Mg-based alloy.

Alloys 1B to 12B shown in Table 11 were used as the alloys of the examples, and alloys 13B to 22B were used as the alloys of the comparative examples.

(deal with)

First, the alloys 1B to 22B were sequentially subjected to a melting step, a dehydrogenation step, a filtration step, and a casting step to prepare an ingot having a thickness of 500 mm.

Then, the aforementioned ingot is processed through a heat treatment step. That is, the aforementioned ingot was held at 350 ° C for 4 hours.

Next, a cut material and a hot rolled material were produced from the ingot after the heat treatment. The cutting material is obtained by treating the aforementioned ingot through a cutting step. The hot rolled material is obtained by subjecting the ingot to hot rolling. Both the cutting material and the hot rolled material are aluminum alloy thick plates with a thickness of 20 mm × a width of 1000 mm × a length of 2000 mm.

Therefore, the cut material after the above treatment is an aluminum alloy thick plate obtained by the production method of the fifth invention, and the hot rolled material after the above treatment is not. Further, only the cutting material using the alloys 1B to 22B belongs to the embodiment of the fifth invention.

Next, the flatness test, the thickness evaluation test, the strength test, and the aluminum oxide film treatability evaluation test were performed about the said cutting material and the hot-rolled material.

The method and evaluation criteria of each test are the same as in the case of the first embodiment.

The test results are shown in Table 12 and Table 13.

Table 12 shows the test results of the cut material. In Table 12, the alloys 1B to 12B belong to the embodiment of the fifth invention, and the alloys 13B to 22B belong to the comparative example. Table 13 shows the test results of the hot rolled product. In Table 13, all of the alloys 1B to 22B belong to the comparative example.

(about cutting materials)

As shown in Table 12, in the case of the alloys 1B to 13B and the alloys 15B to 22B, the processing strain was small and the bending was small. That is, the flatness is good. The plate thickness is also accurate.

In the case of the alloy 14B, since the Mg content exceeds the upper limit value, casting cracks occur and manufacturing cannot be performed. In the case of the alloy 13B, since the Mg content does not reach the lower limit value, the strength is insufficient.

In the case of the alloys 1B to 13B, 17B, and 20B to 22B, the surface appearance after the treatment of the aluminum oxide film did not occur unevenly. In the case of each of the alloys 15B, 16B, 18B, and 19B, since the contents of Si, Fe, Mn, and Cr exceed the upper limit, respectively, a coarse intermetallic compound is formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloys 1B to 13B and 15B to 22B, the surface appearance after the treatment of the aluminum oxide film did not cause unevenness.

Further, in the case of each of the alloys 17B, 20B, 21B, and 22B, since the contents of Cu, Zn, Ti, and Zr each exceed the upper limit value, the effects thereof are saturated, and the economy is not good.

(About hot rolled steel)

As shown in Table 13, in the case of alloys 1B to 13B and 15B to 22B, The machining strain is accumulated and the bending in the rolling direction is large. That is, the flatness is not good. The plate thickness accuracy is almost inferior to that of the cutting material.

In the case of the alloy 14B, since the Mg content exceeds the upper limit value, casting cracks occur and manufacturing cannot be performed. In the case of the alloy 13B, since the Mg content does not reach the lower limit value, the strength is insufficient.

In the case of each of the alloys 15B, 16B, 18B, and 19B, since the contents of Si, Fe, Mn, and Cr exceed the upper limit, respectively, a coarse intermetallic compound is formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloys 1B to 13B and 15B to 22B, the surface appearance after the treatment of the aluminum oxide film was uneven.

(7) Seventh Embodiment

This embodiment relates to the fifth invention. In the present embodiment, the alloy 3B shown in Table 11 was used.

(deal with)

First, the alloy 3B was sequentially subjected to a melting step, a dehydrogenation step, a filtration step, and a casting step to prepare an ingot having a thickness of 500 mm.

Next, the ingot is processed by a heat treatment step. That is, the ingot was heat-treated under the conditions shown in Table 14.

Then, the aforementioned ingot is subjected to a treatment of a cutting step to obtain a cut material. The cutting material is an aluminum alloy thick plate having a thickness of 20 mm × a width of 1000 mm × a length of 2000 mm.

Therefore, the heat treatment conditions are in accordance with the B1 and B2 of the fifth invention, and are examples according to the fifth invention; the heat treatment conditions do not conform to the B3 to B5 of the fifth invention, and are comparative examples.

The flatness evaluation test, the thickness evaluation test, and the machinability evaluation test were performed about the said cutting material.

<flatness evaluation test>

The flatness evaluation was performed by measuring the amount of bending (flatness) per 1 m in the casting direction, and the flatness was 0.4 mm/lm or less, and it was judged as qualified (○), and it was judged to be unqualified when it exceeded 0.4 mm/lm. (×).

<Plate thickness accuracy test>

The plate thickness accuracy evaluation test is the same as in the case of the first embodiment.

<Abrasiveness evaluation test>

Machinability (Evaluation of Cutting Fracture) is a measurement of the number of pieces per unit mass of the chips when drilling with a drill. Specifically, a drill having a diameter of 5 mm was used, and drilling was performed at a number of revolutions of 7000 rpm and a feed rate of 300 mm/min, and the number of chips generated per 10 g was measured. The case of 1000 /10 g or more was judged as pass (○), and the case of less than 1000 /10 g was judged as unacceptable (×).

The test results are shown in Table 14.

As shown in Table 14, the heat treatment conditions of Examples B1 and B2 were in accordance with the fifth invention, and thus the flatness, the sheet thickness precision, and the machinability were good. Further, in Comparative Example B3, since the heat treatment was not performed, the flatness was poor, and the plate thickness accuracy was slightly inferior to those of Examples B1 and B2. In Comparative Example B4, since the treatment temperature was higher than the range of the fifth invention, the machinability was slightly inferior to those of the examples B1 and B2. Further, in Comparative Example B5, since the treatment temperature was lower than the range of the fifth invention, the flatness was poor, and the plate thickness accuracy was slightly inferior to those of the examples B1 and B2.

(8) Eighth embodiment

This embodiment relates to the sixth invention, and the aluminum alloy used in the present embodiment is a 3000-series Al-Mn alloy.

Alloys 23B and 24B shown in Table 15 were used as the alloys of the examples, and alloys 25B and 26B were used as the alloys of the comparative examples.

(deal with)

First, the alloys 23B to 26B were sequentially subjected to a melting step, a dehydrogenation step, a filtration step, and a casting step to prepare an ingot having a thickness of 500 mm.

Next, the ingot is processed by a heat treatment step. That is, the aforementioned ingot was kept at 350 ° C for 4 hours.

Next, a cut material and a hot rolled material were produced from the ingot after the heat treatment. The cutting material is obtained by treating the aforementioned ingot through a cutting step. The hot rolled material is obtained by subjecting the ingot to hot rolling. Both the cutting material and the hot rolled material are aluminum alloy thick plates with a thickness of 20 mm × a width of 1000 mm × a length of 2000 mm.

Therefore, the cut material after the above treatment is an aluminum alloy thick plate obtained by the manufacturing method of the sixth invention, and the hot rolled material after the above treatment is not. Further, only the cutting materials using the alloys 23B and 24B belong to the embodiment of the sixth invention.

Next, the flatness evaluation test, the thickness evaluation test, the strength test, and the aluminum oxide film treatability evaluation test were performed about the said cutting material and the hot-rolled material.

The method and evaluation criteria of each test are the same as in the case of the first embodiment.

Since the characteristics of the thick plate vary depending on the type of the alloy, the evaluation criteria of the strength are as follows. In other words, in the case of strength, the case where the tensile strength was 90 N/mm ² or more was judged as pass (○), and the case where the tensile strength was less than 90 N/mm ² was judged as unacceptable (×).

The test results are shown in Table 16.

(about cutting materials)

As shown in Table 16, in the case of the alloys 23B to 26B, the processing strain was small and the bending was small. That is, the flatness is good, and the plate thickness precision is excellent.

In the case of the alloy 25B, since the Mn content is less than the lower limit, the strength is insufficient. In the case of the alloy 26B, since the Mn content exceeds the upper limit value, a coarse intermetallic compound is formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloys 23B to 26B, the cross-sectional appearance after the treatment of the aluminum oxide film did not cause unevenness.

(About hot rolled steel)

As shown in Table 6, in the case of the alloys 23B to 26B, the machining strain was accumulated, and the bending in the rolling direction was large. That is, the flatness is not good. The plate thickness accuracy is almost inferior to that of the cutting material.

In the case of the alloy 25B, since the Mn content does not reach the lower limit value, the strength is slightly inferior compared to other hot rolled materials. In the case of the alloy 26B, since the Mn content exceeds the upper limit value, a coarse intermetallic compound is formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloys 23B to 26B, the cross-sectional appearance after the treatment of the aluminum oxide film is uneven.

(9) Ninth Embodiment

This embodiment relates to the seventh invention. The aluminum alloy used in this embodiment is a 6000 series Al-Mg-Si alloy.

Alloys 27B and 28B shown in Table 17 were used as the alloys of the examples, and alloys 29B to 32B were used as the alloys of the comparative examples.

(deal with)

First, the alloys 27B to 32B were sequentially subjected to a melting step, a dehydrogenation step, a filtration step, and a casting step to produce an ingot having a thickness of 500 mm.

Next, the ingot is processed by a heat treatment step. That is, the aforementioned ingot was kept at 350 ° C for 4 hours.

Next, a cut material and a hot rolled material were produced from the ingot after the heat treatment. The cutting material is obtained by treating the aforementioned ingot through a cutting step. The hot rolled material is obtained by subjecting the ingot to hot calendering. Both the cutting material and the hot rolled material are aluminum alloy thick plates with a thickness of 20 mm × a width of 1000 mm × a length of 2000 mm.

Further, the obtained cut material and hot rolled material were melted at 520 ° C, and then aged at 175 ° C for 8 hours.

Therefore, the cut material after the above treatment is an aluminum alloy thick plate obtained by the manufacturing method of the seventh invention, and the hot rolled material after the above treatment is not. Further, only the cutting material using the alloys 27B and 28B belongs to the embodiment of the seventh invention.

Next, the cut material and the hot rolled material after the treatment are strengthened. The degree test and the evaluation test of the alumina film treatment property.

The method and evaluation criteria of each test are the same as in the case of the first embodiment.

Since the characteristics of the thick plate vary depending on the type of the alloy, the evaluation criteria of the strength are as follows. In other words, in the case of the strength, the case where the tensile strength was 200 N/mm ² or more was judged as pass (○), and the case where the tensile strength was less than 200 N/mm ² was judged as unacceptable (×).

The test results are shown in Table 18.

(about cutting materials)

As shown in Table 18, in the case of the alloys 29B and 31B, since the Si and Mg contents did not reach the lower limit, respectively, the strength was insufficient. In the case of Alloy 30B Since the Si content exceeds the upper limit value, a coarse intermetallic compound is formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloy 32B, since the Mg content exceeds the upper limit value, the Mg effect is saturated and the economy is poor. In the case of the alloys 27B to 32B, the cross-sectional appearance after the treatment of the aluminum oxide film did not cause unevenness.

(About hot rolled steel)

As shown in Table 18, in the case of the alloys 29B and 31B, since the Si and Mg contents did not reach the lower limit, respectively, the strength was insufficient. In the case of the alloy 30B, since the Si content exceeds the upper limit value, a coarse intermetallic compound is formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloy 32B, since the Mg content exceeds the upper limit value, the Mg effect is saturated and the economy is poor. In the case of the alloys 27B to 32B, the cross-sectional appearance after the treatment of the aluminum oxide film may be uneven.

(10) Tenth Embodiment

This embodiment relates to the eighth invention. The aluminum alloy used in the present embodiment is a 7000-series Al-Zn-Mg-based alloy.

Alloys 33B and 34B shown in Table 19 were used as the alloys of the examples, and alloys 35B to 38B were used as the alloys of the comparative examples.

(deal with)

First, the alloys 33B to 38B were sequentially subjected to a melting step, a dehydrogenation step, a filtration step, and a casting step to produce an ingot having a thickness of 500 mm.

Next, the ingot is processed by a heat treatment step. That is, the aforementioned ingot was kept at 300 ° C for 4 hours.

Next, a cut material and a hot rolled material were produced from the ingot after the heat treatment. The cutting material is obtained by treating the ingot through a cutting step. The hot rolled material is obtained by subjecting the ingot to hot rolling. Both the cutting material and the hot rolled material are aluminum alloy thick plates with a thickness of 20 mm × a width of 1000 mm × a length of 2000 mm.

Further, the obtained cut material and hot rolled material were melted at 470 ° C, and then subjected to aging treatment at 120 ° C for 48 hours.

Therefore, the cut material after the above treatment is an aluminum alloy thick plate obtained by the manufacturing method of the eighth invention, and the hot rolled material after the above treatment is not. Further, only the cutting material using the alloys 33B and 34B belongs to the embodiment of the eighth invention.

Next, the cut material and the hot rolled material after the treatment are strengthened. The degree test and the evaluation test of the alumina film treatment property.

The method and evaluation criteria of each test are the same as in the case of the first embodiment.

Since the characteristics of the thick plate vary depending on the type of the alloy, the evaluation criteria of the strength are as follows. In other words, in the case of the strength, the case where the tensile strength was 250 N/mm ² or more was judged as pass (○), and the case where the tensile strength was less than 250 N/mm ² was judged as unacceptable (×).

The test results are shown in Table 20.

(about cutting materials)

As shown in Table 20, in the case of the alloys 35B and 37B, since the Mg and Zn contents were not below the lower limit, the strength was insufficient. In alloys 36B, 38B In other cases, since the Mg and Zn contents respectively exceed the upper limit value, the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloys 33B to 38B, the cross-sectional appearance after the treatment of the aluminum oxide film did not cause unevenness.

(About hot rolled steel)

As shown in Table 20, in the case of the alloys 35B and 37B, since the Mg and Zn contents were not below the lower limit, the strength was insufficient. In the case of the alloys 36B and 38B, since the Mg and Zn contents respectively exceed the upper limit value, the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloys 33B to 38B, the cross-sectional appearance after the treatment of the aluminum oxide film may be uneven.

(11) Eleventh embodiment

This embodiment relates to the ninth invention. The aluminum alloy used in the present embodiment is a 5000-series Al-Mg-based alloy.

Alloys 1C to 12C shown in Table 21 were used as the alloys of the examples, and alloys 13C to 22C were used as the alloys of the comparative examples.

(deal with)

First, the alloys 1C to 22C were sequentially subjected to a melting step, a dehydrogenation step, a filtration step, and a casting step to prepare an ingot having a thickness of 500 mm.

Next, a cut material and a hot rolled material were produced from the above ingot. The cutting material is obtained by treating the aforementioned ingot through a cutting step. The hot rolled material is obtained by subjecting the ingot to heat rolling after heat treatment. Both the cutting material and the hot rolled material are aluminum alloy thick plates with a thickness of 20 mm × a width of 1000 mm × a length of 2000 mm.

Then, the aforementioned ingot is processed through a heat treatment step. That is, the aforementioned ingot was held at 350 ° C for 4 hours.

Therefore, the cut material after the above treatment is an aluminum alloy thick plate obtained by the manufacturing method of the ninth invention, and the hot rolled material after the above treatment is not. Further, only the cutting material using the alloys 1C to 22C belongs to the embodiment of the ninth invention.

Next, the flatness test, the thickness evaluation test, the strength test, and the aluminum oxide film treatability evaluation test were performed about the said cutting material and the hot-rolled material.

The method and evaluation criteria of each test are the same as in the case of the first embodiment.

Further, since the crystal grain size of the thick plate affects the handleability of the aluminum oxide film, the average crystal grain size of the thick plate is obtained in the same manner as in the case of the first embodiment.

The test results are shown in Table 22 and Table 23.

Table 22 shows the test results of the cut material. In Table 22, the alloys 1C to 12C belong to the embodiment of the ninth invention, and the alloys 13C to 22C belong to the comparative example. Table 23 shows the test results of the hot rolled product. In Table 23, the alloys 1C to 22C are all comparative examples.

(about cutting materials)

As shown in Table 22, in the case of the alloys 1C to 13C and the alloys 15C to 22C, the processing strain was small and the bending was small. That is, the flatness is good. The plate thickness is also accurate.

In the case of the alloy 14C, since the Mg content exceeds the upper limit value, casting cracks occur and manufacturing cannot be performed. In the case of the alloy 13C, since the Mg content does not reach the lower limit value, the strength is insufficient.

In the case of the alloys 1C to 13C, 17C, and 20C to 22C, the surface appearance after the treatment of the aluminum oxide film did not occur unevenly. In the case of each of the alloys 15C, 16C, 18C, and 19C, since the contents of Si, Fe, Mn, and Cr exceed the upper limit, coarse intermetallic compounds are formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloys 1C to 13C and 15C to 22C, the surface appearance after the treatment of the aluminum oxide film does not cause unevenness.

Further, in the case of each of the alloys 17C, 20C, 21C, and 22C, since the contents of Cu, Zn, Ti, and Zr each exceed the upper limit value, the effects thereof are saturated, and the economy is not good.

(About hot rolled steel)

As shown in Table 23, in the case of alloys 1C to 13C and 15C to 22C, The machining strain is accumulated and the bending in the rolling direction is large. That is, the flatness is not good. The plate thickness accuracy is almost inferior to that of the cutting material.

In the case of the alloy 14C, since the Mg content exceeds the upper limit value, casting cracks occur and manufacturing cannot be performed. In the case of the alloy 13C, since the Mg content does not reach the lower limit value, the strength is insufficient.

In the case of each of the alloys 15C, 16C, 18C, and 19C, since the contents of Si, Fe, Mn, and Cr exceed the upper limit, coarse intermetallic compounds are formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloys 1C to 13C and 15C to 22C, the surface appearance after the treatment of the aluminum oxide film was uneven.

(12) The twelfth embodiment

This embodiment relates to the ninth invention. In the present embodiment, the alloy 3C shown in Table 21 was used.

(deal with)

First, the alloy 3C was sequentially subjected to a melting step, a dehydrogenation step, a filtration step, and a casting step to prepare an ingot having a thickness of 500 mm.

Then, the aforementioned ingot is subjected to a treatment of a cutting step to obtain a cut material. The cutting material is an aluminum alloy thick plate having a thickness of 20 mm × a width of 1000 mm × a length of 2000 mm.

Next, the aforementioned cutting material is treated by a heat treatment step. That is, the above-mentioned cutting material was heat-treated under the conditions shown in Table 24.

Therefore, the heat treatment conditions conform to the C1 and C2 of the ninth invention, and are examples of the ninth invention; the heat treatment conditions do not conform to the C3 to C5 of the ninth invention, and are comparative examples.

The flatness evaluation test, the thickness evaluation test, and the machinability evaluation test were performed about the said cutting material.

<flatness evaluation test>

The flatness evaluation is performed by measuring the amount of bending (flatness) per 1 m in the casting direction, and the case where the flatness is 0.4 mm/1 m or less is judged as pass (○), and when it exceeds 0.4 mm/lm, it is judged as not. Qualified (×).

<Plate thickness accuracy test>

The plate thickness accuracy evaluation test is the same as in the case of the first embodiment.

<Abrasiveness evaluation test>

The machinability evaluation test is the same as in the case of the seventh embodiment. The test results are shown in Table 24.

As shown in Table 24, the heat treatment conditions of Examples C1 and C2 were in accordance with the ninth invention, and thus the flatness, the sheet thickness precision, and the machinability were good. Further, in Comparative Example C3, since the heat treatment was not performed, the flatness was poor, and the plate thickness accuracy was slightly inferior to those of Examples C1 and C2. In Comparative Example C4, since the treatment temperature was higher than the range of the ninth invention, the machinability was slightly inferior. Further, in Comparative Example C5, since the treatment temperature was lower than the range of the ninth invention, the flatness was poor, and the plate thickness accuracy was slightly inferior to those of the examples C1 and C2.

(13) The thirteenth embodiment

This embodiment relates to the tenth invention, and the aluminum alloy used in the present embodiment is a 3000-series Al-Mn alloy.

Alloys 23C and 24C shown in Table 25 were used as the alloys of the examples, and alloys 25C and 26C were used as the alloys of the comparative examples.

(deal with)

First, the alloys 23C to 26C are sequentially passed through a melting step to dehydrogenate. The steps, the filtration step, and the casting step were processed to produce an ingot having a thickness of 500 mm.

Next, a cut material and a hot rolled material were produced from the above ingot. The cutting material is obtained by treating the aforementioned ingot through a cutting step. The hot rolled material is obtained by subjecting the ingot to heat rolling after heat treatment. Both the cutting material and the hot rolled material are aluminum alloy thick plates with a thickness of 20 mm × a width of 1000 mm × a length of 2000 mm.

Next, the aforementioned cutting material is treated by a heat treatment step. That is, the aforementioned cut material was kept at 350 ° C for 4 hours.

Therefore, the cut material after the above treatment is an aluminum alloy thick plate obtained by the manufacturing method of the tenth invention, and the hot rolled material after the above treatment is not. Further, only the cutting materials using the alloys 23C and 24C belong to the embodiment of the tenth invention.

Next, the flatness evaluation test, the thickness evaluation test, the strength test, and the aluminum oxide film treatability evaluation test were performed about the said cutting material and the hot-rolled material.

The method and evaluation criteria of each test are the same as in the case of the first embodiment.

Since the characteristics of the thick plate vary depending on the type of the alloy, the evaluation criteria of the strength are as follows. In other words, in the case of strength, the case where the tensile strength was 90 N/mm ² or more was judged as pass (○), and the case where the tensile strength was less than 90 N/mm ² was judged as unacceptable (×).

The test results are shown in Table 26.

(about cutting materials)

As shown in Table 26, in the case of the alloys 23C to 26C, the processing strain was small and the bending was small. That is, the flatness is good, and the plate thickness precision is excellent.

In the case of the alloy 25C, since the Mn content does not reach the lower limit value, the strength is insufficient. In the case of the alloy 26C, since the Mn content exceeds the upper limit value, a coarse intermetallic compound is formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloys 23C to 26C, the cross-sectional appearance after the treatment of the aluminum oxide film did not cause unevenness.

(About hot rolled steel)

As shown in Table 26, in the case of the alloys 23C to 26C, the machining strain was accumulated, and the bending in the rolling direction was large. That is, the flatness is not good. The plate thickness accuracy is almost inferior to that of the cutting material.

In the case of Alloy 25C, since the Mn content does not reach the lower limit value, the strength is slightly inferior to that of other hot rolled materials. In the case of the alloy 26C, since the Mn content exceeds the upper limit value, a coarse intermetallic compound is formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloys 23C to 26C, the cross-sectional appearance of the aluminum oxide film after treatment was uneven.

(14) Fourteenth embodiment

This embodiment relates to the eleventh invention. The aluminum alloy used in this embodiment is a 6000 series Al-Mg-Si alloy.

Alloys 27C and 28C shown in Table 27 were used as the alloys of the examples, and alloys 29C to 32C were used as the alloys of the comparative examples.

(deal with)

First, the alloys 27C to 32C were sequentially subjected to a melting step, a dehydrogenation step, a filtration step, and a casting step to produce an ingot having a thickness of 500 mm.

Next, a cut material and a hot rolled material were produced from the above ingot. The cutting material is obtained by treating the aforementioned ingot through a cutting step. The hot rolled material is obtained by subjecting an ingot to heat rolling after heat treatment. Both the cutting material and the hot rolled material are aluminum alloy thick plates with a thickness of 20 mm × a width of 1000 mm × a length of 2000 mm.

Next, the aforementioned cutting material is treated by a heat treatment step. That is, the aforementioned cut material was kept at 350 ° C for 4 hours.

Further, the obtained cut material and hot rolled material were melted at 520 ° C, and then aged at 175 ° C for 8 hours.

Therefore, the cut material after the above treatment is an aluminum alloy thick plate obtained by the manufacturing method of the eleventh invention, and the hot rolled material after the above treatment is not. Further, only the cutting materials using the alloys 27C and 28C belong to the embodiment of the eleventh invention.

Next, the cut material and the hot rolled material after the treatment are strengthened. The degree test and the evaluation test of the alumina film treatment property.

The method and evaluation criteria of each test are the same as in the case of the first embodiment.

Since the characteristics of the thick plate vary depending on the type of the alloy, the evaluation criteria of the strength are as follows. In other words, in the case of the strength, the case where the tensile strength was 200 N/mm ² or more was judged as pass (○), and the case where the tensile strength was less than 200 N/mm ² was judged as unacceptable (×).

The test results are shown in Table 28.

(about cutting materials)

As shown in Table 28, in the case of alloys 29C and 31C, due to Si, The Mg content does not reach the lower limit value, respectively, and the strength is insufficient. In the case of the alloy 30C, since the Si content exceeds the upper limit value, a coarse intermetallic compound is formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloy 32C, since the Mg content exceeds the upper limit value, the Mg effect is saturated and the economy is poor. In the case of the alloys 27C to 32C, the cross-sectional appearance after the treatment of the aluminum oxide film did not cause unevenness.

(About hot rolled steel)

As shown in Table 28, in the case of the alloys 29C and 31C, since the Si and Mg contents were each less than the lower limit, the strength was insufficient. In the case of the alloy 30C, since the Si content exceeds the upper limit value, a coarse intermetallic compound is formed, and the surface appearance after the treatment of the aluminum oxide film is uneven. In the case of the alloy 32C, since the Mg content exceeds the upper limit value, the Mg effect is saturated and the economy is poor. In the case of the alloys 27C to 32C, the cross-sectional appearance after the treatment of the aluminum oxide film may be uneven.

(15) The fifteenth embodiment

This embodiment relates to the twelfth invention. The aluminum alloy used in the present embodiment is a 7000-series Al-Zn-Mg-based alloy.

Alloys 33C and 34C shown in Table 29 were used as the alloys of the examples, and alloys 35C to 38C were used as the alloys of the comparative examples.

(deal with)

First, the alloys 33C to 38C were sequentially subjected to a melting step, a dehydrogenation step, a filtration step, and a casting step to produce an ingot having a thickness of 500 mm.

Next, a cut material and a hot rolled material were produced from the above ingot. The cutting material is obtained by treating the aforementioned ingot through a cutting step. The hot rolled material is obtained by subjecting the ingot to heat rolling after heat treatment. Both the cutting material and the hot rolled material are aluminum alloy thick plates with a thickness of 20 mm × a width of 1000 mm × a length of 2000 mm.

Next, the aforementioned cutting material is treated by a heat treatment step. That is, the aforementioned cutting material was kept at 300 ° C for 4 hours.

Further, the obtained cut material and hot rolled material were melted at 470 ° C, and then subjected to aging treatment at 120 ° C for 48 hours.

Therefore, the cut material after the above treatment is an aluminum alloy thick plate obtained by the manufacturing method of the twelfth invention, and the hot rolled material after the above treatment is not. Further, only the cutting materials using the alloys 33C and 34C belong to the embodiment of the twelfth invention.

Next, the strength test and the alumina film treatability evaluation test were performed on the cut material and the hot rolled material after the above treatment.

The method and evaluation criteria of each test are the same as in the case of the first embodiment.

Since the characteristics of the thick plate vary depending on the type of the alloy, the evaluation criteria of the strength are as follows. In other words, in the case of the strength, the case where the tensile strength was 250 N/mm ² or more was judged as pass (○), and the case where the tensile strength was less than 250 N/mm ² was judged as unacceptable (×).

The test results are shown in Table 30.

(about cutting materials)

As shown in Table 30, in the case of alloys 35C and 37C, due to Mg, The Zn content does not reach the lower limit value, respectively, and the strength is insufficient. In the case of the alloys 36C and 38C, since the contents of Mg and Zn exceed the upper limit, respectively, the surface appearance after the treatment of the alumina film is uneven. In the case of the alloys 33C to 38C, the cross-sectional appearance after the treatment of the aluminum oxide film did not cause unevenness.

(About hot rolled steel)

As shown in Table 30, in the case of the alloys 35C and 37C, the contents of Mg and Zn were not lower than the lower limit, and the strength was insufficient. In the case of the alloys 36C and 38C, since the contents of Mg and Zn exceed the upper limit, respectively, the surface appearance after the treatment of the alumina film is uneven. In the case of the alloys 33C to 38C, the cross-sectional appearance after the treatment of the aluminum oxide film may be uneven.

The method for producing an aluminum alloy thick plate according to the present invention has excellent productivity, can easily control the surface state and flatness, and can improve the thickness accuracy, so that the industrial use value is high.

S1‧‧‧ melting step

S2‧‧‧ dehydrogenation step

S3‧‧‧Filter step

S4‧‧‧ casting steps

S5‧‧‧ cutting step or heat treatment step

S6‧‧‧ Heat treatment step or cutting step

S7‧‧‧ Surface smoothing process

A‧‧‧Center of thickness direction

B‧‧‧Central part of thickness direction

T‧‧‧ thickness

l‧‧‧Ingot

Fig. 1 is a flow chart showing a method of manufacturing the aluminum alloy thick plates of the first to fourth inventions and the ninth to twelfth inventions.

Fig. 2 is a view showing a central portion in the thickness direction of the ingot removed in the cutting step.

Fig. 3 is a flow chart showing a method of manufacturing the aluminum alloy thick plate of the fifth to eighth inventions.

S1‧‧‧ melting step

S2‧‧‧ dehydrogenation step

S3‧‧‧Filter step

S4‧‧‧ casting steps

S5‧‧‧ cutting step or heat treatment step

S6‧‧‧ Heat treatment step or cutting step

S7‧‧‧ Surface smoothing process

Claims (8)

A method for manufacturing an aluminum alloy thick plate, which is a method for producing an aluminum alloy thick plate from an aluminum alloy, characterized in that the aluminum alloy contains Mg: 1.5% by mass to 12.0% by mass, and contains a mass selected from Si: 0.7. % or less, Fe: 0.8% by mass or less, Cu: 0.6% by mass or less, Mn: 1.0% by mass or less, Cr: 0.5% by mass or less, Zn: 0.4% by mass or less, Ti: 0.1% by mass or less, and Zr: 0.3% by mass At least one of the following, the remainder being composed of Al and unavoidable impurities; and sequentially performing the following steps: a melting step of melting the aluminum alloy, a dehydrogenation step of removing hydrogen from the molten aluminum alloy, and a step of removing the inclusions from the aluminum alloy after removing the hydrogen, a casting step of casting the aluminum alloy from which the inclusions are removed, and a step of cutting the ingot to produce a thick aluminum alloy plate having a predetermined thickness, and a predetermined step The heat-treating step of heat-treating the aluminum alloy thick plate having a thickness of 400 ° C or more at a temperature not exceeding the melting point for 1 hour or more. A method for producing an aluminum alloy thick plate, which is a method for producing an aluminum alloy thick plate from an aluminum alloy, characterized in that the aluminum alloy contains Mn: 0.3% by mass to 1.6% by mass, and contains a mass selected from Si: 0.7. % or less, Fe: 0.8% by mass or less, Cu: 0.5% by mass or less, Mg: 1.5% by mass or less, Cr: 0.3% by mass or less, Zn: 0.4% by mass or less, Ti: 0.1% by mass or less, and Zr: 0.3% by mass or less, and the remainder is Al and The inevitable impurities are formed; and the following steps are sequentially performed: a melting step of melting the aluminum alloy, a dehydrogenation step of removing hydrogen from the molten aluminum alloy, and a filtering step of removing inclusions from the aluminum alloy after removing hydrogen a casting step of casting an aluminum alloy from which inclusions are removed into an ingot, a step of cutting the ingot to produce an aluminum alloy thick plate having a predetermined thickness, and a thickness of the aluminum alloy thick plate having a predetermined thickness of not more than 400 ° C The heat treatment step of heat treatment is carried out while maintaining the temperature of the melting point for 1 hour or more. The invention relates to a method for manufacturing an aluminum alloy thick plate, which is a method for manufacturing an aluminum alloy thick plate from an aluminum alloy, characterized in that the aluminum alloy contains Si: 0.2% by mass to 1.6% by mass, and Mg: 0.3% by mass to 1.5% by mass. %, and is selected from the group consisting of Fe: 0.8% by mass or less, Cu: 1.0% by mass or less, Mn: 0.6% by mass or less, Cr: 0.5% by mass or less, Zn: 0.4% by mass or less, Ti: 0.1% by mass or less, and Zr: At least one of 0.3% by mass or less, the remainder being composed of Al and unavoidable impurities; and sequentially performing the following steps: a melting step of melting the aluminum alloy, and a hydrogen removal from the molten aluminum alloy step, a step of removing the inclusions from the aluminum alloy after removing the hydrogen, a casting step of casting the aluminum alloy from which the inclusions are removed into an ingot, and a step of cutting the ingot to produce a thick aluminum alloy plate having a predetermined thickness, and A heat treatment step of heat treatment for a predetermined thickness of an aluminum alloy thick plate at a temperature of 400 ° C or higher and a temperature not exceeding the melting point for 1 hour or more. The invention relates to a method for manufacturing an aluminum alloy thick plate, which is a method for manufacturing an aluminum alloy thick plate from an aluminum alloy, characterized in that the aluminum alloy contains Mg: 0.4% by mass to 4.0% by mass, and Zn: 3.0% by mass to 9.0% by mass. %, and is selected from the group consisting of Si: 0.7 mass% or less, Fe: 0.8 mass% or less, Cu: 3.0 mass% or less, Mn: 0.8 mass% or less, Cr: 0.5 mass% or less, and Ti: 0.1 mass% or less, Zr: At least one of 0.25 mass% or less, the remainder being composed of Al and unavoidable impurities; and sequentially performing the following steps: melting step of melting the aluminum alloy, and dehydrogenation of hydrogen from the molten aluminum alloy a step of removing the inclusions from the aluminum alloy after removing the hydrogen gas, a casting step of casting the aluminum alloy from which the inclusions are removed into an ingot, and a cutting step of cutting the ingot to produce an aluminum alloy thick plate having a predetermined thickness A heat treatment step of heat-treating the aluminum alloy thick plate of a predetermined thickness by maintaining the temperature at 350 ° C or higher and not reaching the melting point for 1 hour or more. An aluminum alloy as described in any one of claims 1 to 4 In the method for producing a thick plate, after the heat treatment step, a surface smoothing treatment step is performed to perform surface smoothing treatment on the surface of the aluminum alloy thick plate. The method for producing an aluminum alloy thick plate according to the fifth aspect of the invention, wherein the surface smoothing treatment is performed by one or more selected from the group consisting of a cutting method, a grinding method, and a polishing method. The method for producing an aluminum alloy thick plate according to any one of claims 1 to 4, wherein in the cutting step, the central portion in the thickness direction is removed from the ingot; and the central portion in the thickness direction is Each of the surfaces in the thickness direction in the thickness direction has a uniform thickness, and in the case where the thickness of the ingot is T, the total thickness is T/30 to T/5. An aluminum alloy thick plate, which is produced by the method for producing an aluminum alloy thick plate according to any one of claims 1 to 4, and has an average crystal of 400 μm or less. Particle size.