309 stainless steel is an international stainless steel labeling method. 309S Stainless Steel - S30908 (U.S. AISI, ASTM) 309S corresponding grades are 0Cr23Ni13 Chinese characteristics and uses: corrosion resistance, heat resistance than 0Cr19Ni9 good.
Chemical composition
① chemical element with the symbol of international and national symbols to represent the chemical composition, with the Arabic alphabet to represent the components of content: such as: China, Russia 12CrNi3A ② fixed number of digits to represent the number of steel series or class; such as: USA, Japan, 300 series, 400 series, 200 series; ③ the order form with the Latin alphabet and numbers, saying only that purpose. The number of China's rules ① ② use elemental symbols, Hanyu Pinyin, open-hearth steel: P, boiling steel: F, killed steel: B, A Steel: A, T8: Special 8, GCr15: Ball ◆ structural steel, spring steel such as: 20CrMnTi 60SiMn, (with very few that C content) ◆ stainless steel, alloy tool steel (with a few thousandths of said C content), such as: 1Cr18Ni9 thousandth (ie, 0.1% C), stainless steel C ≤ 0.08% as 0Cr18Ni9, ultra-low carbon C ≤ 0.03% as 0Cr17Ni13Mo