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 post-weld heat treatment of all weld repairs affecting surfaces intended to be wetted by the corrosive medium. For applications for which post-weld heat treatment is not considered mandatory for retention of acceptable corrosion resistance, refer to Specification A743/A743M.

Note 1: For general corrosion-resistant alloy castings, reference should be made to Specification A743/A743M. For general heat-resistant alloy castings, reference should be made to Specification A297/A297M. For nickel-base alloy castings, refer to Specification A494/A494M.

1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.

1.3.1 Within the text, the SI units are shown in brackets.

1.3.2 Inch-pound units are applicable for material ordered to Specification A744 and SI units for material ordered to Specification A744M.

1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.