304 stainless steel plate national plate number

　　Old grade standard for 304 stainless steel plate: GB/T4237-1992 0Cr18Ni9

　　New grade standard for 304 stainless steel plate: GB24511-2009 06Cr19Ni10

　　Stainless steel American standard grade

　　American Standard: ASTM A240/A240M 304

　　The American Iron and Steel Institute uses three digits to indicate various standard grades of malleable stainless steel. Among them: ① Austenitic stainless steel is marked with numbers from the 200 and 300 series.

　　② Ferritic and martensitic stainless steels are represented by 400 series numbers. For example, some more common austenitic stainless steels are labeled with 201, 304, 316, and 310.

　　③ Ferritic stainless steel is marked with 430 and 446, and Martensitic stainless steel is marked with 410, 420 and 440C. It is dual phase (austenite ferrite).

　　④ Stainless steel precipitation hardening stainless steel and high alloys with iron content less than 50% are usually named using patent or trademark names.

　　Standard classification and grading

　　4-1 Classification: ① National Standard GB ② Industry Standard YB ③ Local Standard ④ Enterprise Standard Q/CB

　　4-2 Classification: ① Product standards ② Packaging standards ③ Method standards ④ Basic standards

　　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 Bars (Grade I) GB4241-84 Stainless Welding Plate (Grade H) GB4356-84 Stainless Welding Plate (Grade I) GB1270-80 Stainless Pipe (Grade I) GB12771-91 Stainless Welding Pipe (Grade Y) GB3280-84 Stainless Cold Plate (Grade I) GB4237-84 Stainless Hot Plate (Grade I) GB4239-91 Stainless Cold Strip (Grade I)