Corrosion Resistance and Mechanical Properties of a 140 ksi min Alloy 945X for HPHT ApplicationsSarwan Mannan Special Metals Corporation Huntington WV 25705 USA A newly developed INCOLOY alloy 945X has nominal composition of Fe-53.5Ni-20.5Cr-3Mo-2Cu-4Nb-1.5Ti. The alloy provides 140 ksi (965 MPa) minimum yield strength with an excellent combination of ductility and impact strength in the solution treated and aged condition. Alloy 945X is ISO 15156 / NACE MR0175 approved to level VII and level VI at 450F (232C°). This paper covers alloy 945X capabilities for mechanical properties and microstructure. The data include high temperature de-rating fatigue and fracture toughness at room temperature and high temperature. Further results on slow strain rate testing (SSRT) are presented on a wide range of yield strengths and product dimensions. This data on SSRT is compared with other high strength alloys.