Alloy 904L (UNS N08904) is a super austenitic stainless steel is designed for moderate to high corrosion resistance in a wide range of process environments. The combination of high chromium and nickel content, coupled with additions of molybdenum and copper, assure good to excellent corrosion resistance. With its highly alloyed chemistry—25% nickel and 4.5% molybdenum, 904L provides good chloride stress corrosion cracking resistance, pitting, and general corrosion resistance superior to 316L and 317L molybdenum enhanced stainless steels. Alloy 904L was originally developed to withstand environments containing dilute sulfuric acid. It also offers good resistance to other inorganic acids such as hot phosphoric acid as well as most organic acids. This Grade is better than 316 stainless in many environments.

Related Specifications
1.4539 BS EN 10088 1 3 EN 10272 NACE MR0175
UNS ASTM A182 UNS ASME SB649 N08904 AISI 904