① Austenitic stainless steel is marked with 200 and 300 series numbers,
② Ferritic and martensitic stainless steels are represented by 400 series numbers. For example, some common austenitic stainless steels.
It is marked with 20 1, 305, 3 16, 3 10.
③ ferritic stainless steel is marked with 430 and 446, and martensitic stainless steel is marked with 4 10, 420 and 440C.
Remember, biphasic (austenite-ferrite),
④ Stainless steel, precipitation hardened stainless steel and high alloy with iron content less than 50% usually adopt patent names or trade names.