The selection of materials of construction, including the final heat treatment, is a major factor in the success of many processes in an oil refinery. Alloys UNS N08800, N08810, N08811, and N08825 are each used in refinery applications and have the excellent corrosive resistance and mechanical properties required for the demanding service conditions. These materials always undergo some amount of fabrication or welding prior to going into service. In many cases, a postweld/
fabrication heat treatment is not necessary; however, in some cases, it is beneficial to heat treat these alloys after fabrication and welding. This paper will describe guidelines for when a postweld/ fabrication heat treatment should be considered and applicable welding products and heat treat procedures.
Keywords: Alloys 800, 800H, 800HT and 825, hot working, cold working, annealing, joining.