Stainless Steel 904L, UNS N08904, 1.4539 Chemical composition
Fe, <0.02% C, 19-23% Cr, 23-28% Ni, 4-5% Mo, <2.0% Mn, <1.0% Si, <0.045% P, <0.035% S, 1.0-2.0% Cu
SS 904l Properties
|Grade||Tensile Strength (MPa) min||Yield Strength 0.2% Proof (MPa) min||Elongation (% in 50mm) min||Hardness|
|Rockwell B (HR B)||Brinell (HB)|
|SS 904L||490||220||36||70-90 typical||150|
|Mean Co-eff of Thermal Expansion (µm/m/°C)||Thermal Conductivity
|Specific Heat 0-100°C
|0-100°C||0-315°C||0-538°C||At 20°C||At 500°C|
SS904L stainless steels have excellent resistance to warm seawater and chloride attack. The high resistance of SUS 904L stainless steel against stress corrosion cracking is due to the presence of high amounts of nickel in its composition. Moreover, the addition of copper to these grades develops resistance to sulphuric acid and other reducing agents in both aggressive and mild conditions.
The corrosion resistance of 904L is intermediate between super austenitic grades, with 6% molybdenum content, and standard SUS316L austenitic grades. stainless steel grade 904L is less resistant to nitric acid than grades SUS304L and SUS310L, which are free of molybdenum. This steel grade needs to be solution treated following cold working, to achieve maximum stress corrosion cracking resistance under critical environments.