S39042 (904L)

Just search on Baidu and you’ll find out. . . This is not duplex stainless steel. . 904L (N08904, 14539) is a super austenitic stainless steel that contains 14.0–18.0% chromium, 24.0–26.0% nickel, and 4.5% molybdenum. 904L super austenitic stainless steel is a low-carbon, high-nickel and molybdenum austenitic acid-resistant stainless steel, and it is a proprietary material introduced from the French company H·S. It exhibits excellent activation-passivation transition capabilities, as well as very good corrosion resistance. It shows good resistance to corrosion in non-oxidizing acids such as sulfuric acid, acetic acid, formic acid, and phosphoric acid. It also possesses good pitting resistance in neutral chloride-containing media, along with excellent resistance to crevice corrosion and stress corrosion. It is suitable for sulfuric acids of various concentrations at temperatures below 70°C; it exhibits excellent corrosion resistance under normal pressure in acetic acid of any concentration and at any temperature, as well as in mixed acids of formic acid and acetic acid