ALLOY 904L • UNS N08904 • WNR 1.4539

UNS NO8904, commonly known as 904L, is a low carbon high alloy austenitic stainless steel which is widely used in applications where the corrosion properties of AISI 316L and AISI 317L are not adequate.

The addition of copper to this grade gives it corrosion resistant properties superior to the conventional chrome nickel stainless steels, in particular to sulphuric, phosphoric and acetic acids. However, there is limited use with hydrochloric acids. It also has a high resistance to pitting in chloride solutions, a high resistance to both crevice and stress corrosion cracking. Alloy 904L performs better than other austenitic stainless steels due to the higher alloying of nickel and molybdenum.