UNS N07022 alloy, with a nominal composition of Ni-21Cr-17Mo (wt.%), has found success in demanding applications requiring excellent corrosion resistance and high strength. It has been incorporated in the NACE MR0175 / ISO 15156 and NACE MR0103 / ISO 17945 standards at the highest test levels. The focus of this paper is the welding metallurgy and weld metal properties of N07022 alloy. Evaluation of the N07022 weld metal microstructure will be discussed. Sour gas testing of N07022 weld overlay material will be highlighted, including slow strain rate tensile test results in the NACE Level VII environment of 25% NaCl + 500 psi (3.45 MPa) CO2 + 500 psi (3.45 MPa) H2S, at temperatures as high as 550°F (288°C). In addition, weld mechanical properties will be presented, including transverse weld tensile and all-weld-metal tensile test results. The overall results demonstrate the suitability of N07022 alloy for demanding welded applications.
Key words: Nickel-Base Alloys, N07022, C-22HS, Welding, Overlay, NACE MR0175, Sour Gas