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

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 AASHTO M 163M/M 163.

Note—For general corrosion-resistant alloy castings, reference should be made to AASHTO M 163M/M 163. For general heat-resistant alloy castings, reference should be made to ASTM A297/A297M. For nickel-base alloy castings, refer to ASTM A494/A494M.

The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the inch-pound units are shown in brackets. 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. SI units are applicable for material ordered to M 285M and inch-pound units for material ordered to M 285.