This specification covers standard requirements for iron-chromium-nickel alloy, stainless steel castings intended for particularly severe corrosive applications. Alloys shall be melted by the electric furnace process with or without refining such as argon-oxygen-decarburization. Castings shall be heat treated and shall conform to the required heat treatment conditions. The materials shall conform with the prescribed chemical requirements for carbon, manganese, silicon, phosphorus, sulfur, chromium, nickel, molybdenum, columbium, copper, selenium, tungsten, vanadium, iron, and nitrogen.

1.1 This specification covers iron-chromium-nickel alloy, stainless steel castings intended for particularly severe corrosive applications.

1.2 This specification requires postweld heat-treatment of all weld repairs affecting surfaces intended to be wetted by the corrosive medium. For applications for which postweld heat-treatment is not considered mandatory for retention of acceptable corrosion resistance, refer to Specification A 743/A 743M. Note 1For general corrosion-resistant alloy castings, reference should be made to Specification A 743/A 743M. For general heat-resistant alloy castings, reference should be made to Specification A 297/A 297M. For nickel-base alloy castings, refer to Specification A 494/A 494M.

1.3 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification. Inch-pound units are applicable for material ordered to Specification A 744 and SI units for material ordered to Specification A 744M.