Shuji Hashizume of Tenaris NKK Tubes, Japan, discussed high-strength, low-carbon, 13% chromium martensitic stainless steels at MS&T 2019 in Portland, Oregon. These steels have been widely used in the oil and gas industries because of their high strength and excellent corrosion resistance in carbon dioxide-containing corrosive environments. Recently, corrosion-resistant grades with strength higher than 110 ksi have been developed by additions of niobium and molybdenum. The resulting NbC and solution Mo could contribute high strength.
In this paper, the effects of Nb and Mo addition on mechanical property and corrosion resistance of low carbon – 13%Cr martensitic stainless steel were reviewed. SSC resistance at room temperature and SCC resistance at high temperature were discussed. As a conclusion, molybdenum additions were more effective for strengthening of 13%Cr steels at high temperature. This was caused by the formation of more-corrosion-resistant chromium oxide and molybdenum oxide films.
Title: Effects of Nb and Mo Addition for Strengthening Corrosion Resistance of 13%Cr Steels
Author: Shuji Hashizume; Tenaris NKK Tubes
