This specification covers standards for iron-chromium and iron-chromium-nickel alloy castings of general purpose grades (Grades HF, HH, HI, HK, HE, HT, HU, HW, HX, HC, HD, HL, HN, and HN) applicable in heat-resistant services. Alloys shall be produced through electric arc, electric-induction, or other approved processes. Heat-treatment shall be conducted when agreed upon by the manufacturer and purchaser. The material shall conform to carbon, manganese, silicon, phosphorus, sulfur, chromium, nickel, and molybdenum contents. Tensile requirements including tensile strength, yield point, and elongation shall apply when specified in the purchase order. Guidelines for repair by welding are also given.

1.1 This specification covers iron-chromium and iron-chromium-nickel alloy castings for heat-resistant service. The grades covered by this specification are general purpose alloys and no attempt has been made to include heat-resisting alloys used for special production application.

Note 1—For heat-resisting alloys used for special product application, reference should be made to Specification A 351/A 351M, A 217/A 217M, and A 447/A 447M.

1.2 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 non-conformance with the standard.