904L (N08904, 14539) super-austenitic stainless steel 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 steel with excellent activation-passivation transition capabilities. It boasts exceptional corrosion resistance, excellent resistance to corrosion in non-oxidizing acids, and excellent resistance to pitting in neutral chloride-containing media. Additionally, it offers good resistance to crevice corrosion and stress corrosion.

Super Austenitic Stainless Steel 904L (00Cr20Ni25Mo4.5Cu; UNS: N08904; EN: 1.4539) is a low-carbon, high-alloy austenitic stainless steel with excellent corrosion resistance in dilute sulfuric acid, designed for environments with severe corrosive conditions. It boasts high chromium and sufficient nickel content, with added copper enhancing its strong acid resistance, particularly against chloride pitting and stress corrosion cracking. It resists pitting and cracking, has slightly better resistance to pitting corrosion than other steels, and offers good machinability and weldability, suitable for pressure vessels.