How to name Aluminum Alloy in China?

According to the provisions of GB/T16474, China Aluminum Alloy whose chemical composition is the same as the alloys named by the International Trademark Registration Agreement for Deformed Aluminum and Aluminum Alloys shall use the international 4-digit system grade directly, and shall not be deformed with the international 4-digit system grade. Although the aluminum alloy is in line with the standard, although the four-character grade is used, the experimental aluminum alloy is added with X before the four-character grade, and the chemical composition is registered as required. The four-character designation method shall comply with the provisions of the four-character system designation method.
The first, third and fourth digits of the four-digit character system are Arabic numerals, and the second is English capital letters. The first digit of the grade indicates the group of aluminum alloys. Except for modified China aluminum alloy, the aluminum alloy groups are determined according to the main alloying elements. For example: 7A52, 7B52 alloy main alloying elements refer to the alloying elements with the maximum limit content arithmetic mean. When there is more than one alloying element with the maximum arithmetic mean of limit content, the alloy group shall be determined in the order of Cu, Mn, Si, Mg, Zn and other elements. The second letter of the grade indicates the modification of the original pure aluminum or aluminum alloy, and the last two digits are used to identify different aluminum alloys in the same group or to indicate the purity of aluminum, such as 1060 alloy.
1. Nomenclature of pure aluminum grades
When the AL content is not less than 99.00%, it is pure aluminum, and its grade is represented by the 1xxx series. For example, the last two digits of the 1035 alloy grade indicate the minimum percentage of AL content. When the minimum AL content percentage is accurate to 0.01%, the last two digits of the grade are the two decimal places in the minimum AL content percentage. The letter in the second digit of the grade indicates the modification of the original pure aluminum. If the letter in the second digit is A, it means the original pure aluminum; if it is the letter B-Y, it means the modification of the original pure aluminum, and its element content is slightly changed compared with the original pure aluminum.
2. Nomenclature of aluminum alloy grades
The grades of aluminum alloys are represented by the 2xxx-8xxx series. The last two digits of the grade have no special meaning and are only used to distinguish different aluminum alloys in the same group. The letter in the second digit of the grade indicates the modified condition of the original alloy. If the letter in the second digit of the grade is A, it means the original alloy; if it is the letter B-Y, it means the modified alloy of the original alloy. Compared with the original alloy, the change in chemical composition of the modified alloy is limited to the alloy content in the form of one alloying element or a group of alloying elements, and the change in the arithmetic mean of the limit content is in compliance with the regulations.