Stainless steels can be considered as good candidates for use in H2S-CO2 containing gas fields provided that their limits of use are accurately known. As the main problem for these materials is the resistance to stress corrosion cracking, laboratory tests were conducted on various stainless steels either austenitics or duplexes in NACE TM 01-77solution as well as in simulating field environments. The combination of Constant Load and Slow Strain Rate tests results permitted stating conservative limiting environmental conditions for SCC expressed as PH2S and temperature values. Moreover, the resistance of tbe steels appeared to be mainly dependent on their chemical composition by considering chromium, molybdenum and nitrogen additions (PREN).
Keywords : oil & gas, sour gas, localized corrosion, stress corrosion cracking, duplex stainless steel, super-austenitic stainless steel, nitrogen, alloying elements