Stainless Steel 904L is a high-alloy austenitic stainless steel with low carbon content. The grade is intended for use under severe corrosive conditions. It has been application proved over many years and was originally developed to resist corrosion in dilute sulfuric acid. It is standardized and approved for pressure vessel use in several countries.
UNS NO8904, commonly known as stainless steel 904L, is a low carbon high alloy austenitic stainless steel which is widely used in applications where the corrosion properties of AISI stainless steel 316L and AISI stainless steel 317L are not adequate.
Stainless Steel 904L is a low carbon high alloy austenitic stainless steel, with an chromium, nickel, molybdenum and copper content, which is widely used in applications where the corrosion properties of Stainless Steel 316L & Stainless Steel 317L are not adequate. although originally develop for greatly improved resistance to strong reducing acids, particularly sulphuric acid. It also has an very high resistance to a wide range of environments. This feature has been verified that it is very successful after many years of practical applications, which has results that Stainless Steel 904L has been standardized in many countries.
Stainless Steel 904L is a non-stabilised low carbon high alloy austenitic stainless steel. The addition of copper to this grade gives it greatly improved resistance to strong reducing acids, particularly sulphuric acid. It is also highly resistant to chloride attack - both pitting crevice corrosion and stress corrosion cracking. This grade is non-magnetic in all conditions and has excellent weldability and formability. The austenitic structure also gives this grade excellent toughness, even down to cryogenic temperatures. Stainless Steel 904L does have very substantial contents of the high cost ingredients nickel and molybdenum. Many of the applications in which this grade has previously performed well can now be fulfilled at lower cost by duplex stainless steel 2205 (S31803 or S32205), so it is used less commonly than in the past.
