EFFECTS OF Nb AND Mo ADDITION FOR STRENGTHENING ON CORROSION RESISTANCE OF 13Cr STEELS

摘要

Low C - 13%Cr martensitic stainless steels have been widely used for oil and gas industries because of their high strength and excellent corrosion resistance in CO_2 containing corrosive conditions. Recently, higher strength than 110 ksi grade corrosion resistant alloys have been developed by Nb and Mo addition. NbC and solution Mo could contribute high strength. In this paper, effects of Nb and Mo addition on mechanical property and corrosion resistance of low C - 13%Cr martensitic stainless steel were reviewed. SSC resistance at room temperature and SCC resistance at high temperature were discussed. As a conclusion, Mo addition was more effective for strengthening of 13%Cr steels with excellent corrosion resistance at high temperature. This would be achieved by forming more resistant Cr and Mo oxide films.