Numbering and representation of steel

① Use the international chemical element symbol and the symbol of the country to indicate the chemical composition, and use the Arabic alphabet to indicate the component content:

For example: China, Russia 12CrNi3

② Use fixed digit numbers to represent steel series or numbers; Such as: United States, Japan, 300 systems, 400 systems, 200 systems;

③ Use the Latin alphabet and order to form the serial number, only to indicate the purpose.

Chinese numbering rules

① Use element symbols

② Application, Chinese Pinyin, open-hearth steel: P, boiling steel: F, killed steel: B, Class A steel: A, T8: special 8, GCr15: ball

◆ Alloy steel, spring steel, such as: 20CrMnTi 60SiMn, (with a few tens of thousands of C content)

◆ Stainless steel, alloy tool steel (with a few thousandths of C content), such as: 1Cr18Ni91/000C (i.e. 0.1%C), stainless C≤0.08% such as 0Cr18Ni9, ultra-low carbon C≤0.03% such as 00Cr17Ni13Mo

International stainless steel labeling method

The American Iron and Steel Institute uses three digits to label various standard grades of malleable stainless steel. Among them:

① Austenitic stainless steels are marked with 200 and 300 series numbers, for example, some of the more common austenitic stainless steels are marked with 201, 304, 316 and 310.

② Ferrite and martensitic stainless steel are represented by 400 series numbers.

③ Ferritic stainless steel is marked with 430 and 446, and martensitic stainless steel is marked with 410, 420 and 440C.

④ Biphase (austenite-ferrite), stainless steel, precipitation-hardened stainless steel and high alloys with iron content of less than 50% are usually named by patent names or trademarks.

4). Standard classification and grading

4-1 Classification Classification:

① National standard GB ② Industry standard YB ③ Local standard ④ Enterprise standard Q/CB

4-2 Categories:

① Product standards ② packaging standards ③ method standards ④ basic standards

4-3 Standard level (three levels) :

Y level: International advanced level I level: international general level H level: domestic advanced level

4-4 National standard

GB1220-84 Stainless bar (Grade I) GB4241-84 stainless welding disk (Grade H)

GB4356-84 Stainless welding disk (Class I) GB1270-80 stainless pipe (Class I)

GB12771-91 Stainless welded pipe (Y level) GB3280-84 stainless cold plate (I level)

GB4237-84 Stainless hot plate (Class I) GB4239-91 Stainless Cold Belt (Class I)