Except Grade A steel and killed steel, other status symbols of steel are: open hearth steel: P, boiling steel: F, T8: special 8, GCr 15: ball. Stainless steel belongs to a kind of steel, "304" is a general model, which is 1Cr 18Ni9 in the national standard, and the standard composition is 18% chromium and 8% nickel. It is a non-magnetic stainless steel, and its metallographic structure will not be changed by heat treatment.
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International stainless steel marking method
The American Iron and Steel Association uses three numbers to represent various standard grades of malleable stainless steel. These include:
1, austenitic stainless steel is marked with 200 and 300 series numbers. For example, some common austenitic stainless steels are marked with 20 1, 304, 3 16, 3 10.
2. Ferritic and martensitic stainless steels are represented by 400 series numbers.
3. Ferritic stainless steel is marked with 430 and 446, and martensitic stainless steel is marked with 4 10, 420 and 440C.
4. Duplex (austenite-ferrite), stainless steel, precipitation hardening stainless steel and high alloy with iron content below 50% are usually named by patent names or trademarks.
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