904L super austenitic stainless steel (C max 0.02%, Cr 19.0-23.0%, Ni 23.0-28.0%, Mo 4.0-5.0%, Cu 1.0-2.0%) offers excellent resistance to sulfuric acid and chloride pitting. Applied in petroleum and petrochemical reactors, sulfuric acid storage and transport equipment, heat exchangers and flue gas desulfurization plants.