1 Basic principles of aluminum grade naming
(1) International four-digit system grade
① Division of international four-digit system grade groups
The first digit of the international four-digit system grade indicates the group, as shown below:
a. Pure aluminum (aluminum content not less than 99.00%) 1xxx (grade example 1285 1085 1070 1070A 1050A 1035
b. Alloy groups are divided according to the following main alloying elements
Mg+Si 6xxx (grade example 6061 6063
Cu2XXX (grade example 2014 2014A 2024 2124) 6063A 6082)
Mn3XXX (grade example 3003 3005 3103 3105) Zn7XXX (grade example 7003 7005
7049A 7085)
Si 4XXX (Examples of brands: 4004 4032 4043 4043A) Other elements 8XXX (Examples of brands: 80018011 8011A 8090)
Mg5XXX (Examples of brands: 5005 5019 5050 5154A) Spare group 9XXX
② International four-digit system 1XXX brand series
In 1XXx, the last two digits indicate the minimum aluminum content, which is the same as the two digits to the right of the decimal point in the minimum aluminum content. For example, 1060 indicates industrial pure aluminum with a minimum aluminum content of 99.60%. The first digit indicates the modification of the impurity range. If it is zero, it means that the impurity range of the industrial pure aluminum is the normal range in production; if it is a natural number from 1 to 9, it means that one or several impurities or alloy elements should be specially controlled in production. For example, 1350 industrial pure aluminum is an electrical aluminum with an aluminum content of ≥99.50%, of which 3 impurities should be controlled, namely w(V+Ti)≤0.02%, w(B)≤0.05%, ω(Ca)≤0.03%.
③ International four-digit system 2XXX~8XXX brand series
In the 2xxx~8xxx series, the last two digits of the brand have no special meaning, and only represent different alloys in the same series. However, some represent the digital part of the old brand used by Alcoa in the past, such as 2024 alloy, which is the former 24S alloy. However, there are very few such alloys. The second digit represents the modification of the alloy. If it is zero, it means the original alloy. If it is any integer from 1 to 9, it means the number of modifications to the alloy. The modification of the original alloy is limited to one or more of the following situations:
a. Change the content range of the main alloying elements, but the relationship between the maximum change and the content of the alloying elements in the original alloy is as follows:
Within the arithmetic mean range of the alloying element content in the original alloy/% Maximum allowable change/%
≤1.0% 0.15
>1.0~2.0 0.20
>2.0~3.0 0.25
>3.0~4.0 0.30
>4.0~5.0 0.35
>5.0~6.0 0.40
>6.0 0.50
b. Add or delete an alloying element whose arithmetic mean of limit content does not exceed 0.30%, or add or delete an alloying element in the form of a group of combined elements whose arithmetic mean of limit content does not exceed 0.40%.
c. Replace another alloying element with an alloying element of the same function. d. Change the impurity content range.
e. Change the grain refiner content range.
f. Use high-purity metal to reduce the maximum limit values of iron and silicon content to 0.12%, 0.10% or less respectively.
④ Grades of test alloys
The grades of test alloys are also compiled according to the above provisions, but with a capital letter "X" in front of the number. The registration period of test alloys shall not exceed 5 years. The unit applying for registration has the right to change the composition of the test alloy. When the alloy passes the test, "X" is removed and it becomes a formal alloy.
Note:
1. The international digital system grades of wrought aluminum and aluminum alloys refer to the grades named according to the recommended method of the international grade naming system for wrought aluminum and aluminum alloys formulated in December 1970. This recommended method is proposed by groups or organizations around the world that recognize the declaration of the international grade system agreement for wrought aluminum and aluminum alloys. The grade and composition registration secretariat is located in the American Aluminum Association (AA).
2. International four-digit system of similar aluminum and aluminum alloy grades: Similar aluminum and aluminum alloys between countries refer to pure aluminum or aluminum alloys newly registered in a certain country with similar composition to a certain registered grade. Similar aluminum and aluminum alloys between countries are named by a four-digit suffix with similar composition and an English capital letter (in the order of the international alphabet, starting from A, but excluding I.0.Q).
(2) Deformed aluminum and aluminum alloys that are not named as international four-digit system grades should be named by a four-character grade (but experimental aluminum and aluminum alloys are named by the prefix X plus a four-character grade).