Number and representation of steel
① Use international chemical element symbols and symbols of the country to represent chemical components, and Arabic letters to represent component content:
Such as: China, Russia 12CrNi3
②Use fixed-digit numbers to represent steel series or numbers; such as: the United States, Japan, 300 series, 400 series, 200 series;
③The serial number is composed of Latin letters and sequence, which only indicates the purpose.
China's numbering rules
①Using element symbols
②Purpose, 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, (using a few ten thousandths to express the content of C)
◆Stainless steel, alloy tool steel (use a few thousandths to express the content of C), such as: 1Cr18Ni9 one thousandth (ie 0.1% C), stainless C≤0.08% such as 0Cr18Ni9, ultra-low carbon C≤0.03% such as 00Cr17Ni13Mo
International stainless steel marking method
The American Iron and Steel Institute uses three digits to indicate various standard grades of forgeable stainless steel. among them:
①Austenitic stainless steels are marked with 200 and 300 series numbers. For example, some common austenitic stainless steels are marked with 201, 304, 316 and 310.
②Ferritic and martensitic stainless steels are represented by numbers in the 400 series.
③Ferritic stainless steel is marked with 430 and 446, and martensitic stainless steel is marked with 410, 420 and 440C.
④ Duplex (austenite-ferrite), stainless steel, precipitation hardening stainless steel, and high alloys with iron content less than 50% are usually named by patent names or trademarks.
4). Standard classification and classification
①National standard GB ②Industry standard YB ③Local standard ④Enterprise standard Q/CB
①Product standard ②Packaging standard ③Method standard ④Basic standard
4-3 Standard level (divided into three levels):
Y level: international advanced level I level: international general level H level: domestic advanced level
4-4 National Standard
GB1220-84 stainless steel bar (level I) GB4241-84 stainless steel welded plate (level H)
GB4356-84 Stainless Steel Welded Panel (Class I) GB1270-80 Stainless Steel Pipe (Class I)
GB12771-91 Stainless steel welded pipe (Grade Y) GB3280-84 Stainless steel cold plate (Grade I)
GB4237-84 stainless hot plate (level I) GB4239-91 stainless cold belt (level I)