Steels containing up to 5% Cr were investigated with respect to their corrosion performance in oil and gas environments. Steels containing 3%Cr or more showed improved corrosion performance over Cr
free steel by a factor of two or more in a sweet corrosion environment. 5% Cr steel, however, showed deeper localized corrosion than 3% Cr steel under simulated seawater injection conditions with some oxygen contamination. Although Cr containing steels showed rather poor SSC resistance, the resistance was improved by Mo addition.
Key words: CO2 corrosion, oil country tubular goods (OCTG), Cr bearing steel, sulfide stress cracking, sea water injection.