Evaluation of Highly Alloyed Stainless Materials for CO₂/H₂S Environments

Martensitic, autstenitic, ferritic-austenitic, and high-nickel stainless steels and high-iron, nickel-base alloys are tested for their resistance to localized corrosive attack and to stress corrosion cracking in media containing chloride, saturated with CO₂/H₂S gas. Several testing environments are used in order to simulate service applications in deep H₂S wells, deep CO₂ wells, and enhanced recovery by CO₂ injection. The alloys' performances are compared at different strength levels (0, 20, and 50% cold work), and the effects of temperature and CO₂/H₂S content are examined. The overall resistance of each class of alloys is outlined. Furthermore, within the same class of alloys, the differences are described with respect to localized corrosion and to stress corrosion cracking resistance.