Corrosion behavior of sulfide-resistant casing steel PllOSS under condition of high containing H2S/CO2 and Cl-

High temperature/pressure autoclave was used to simulate the high containing H2S/CO2 corrosion environment, the influences of Cl- on corrosion rate, sulfide stress cracking and hydrogen induced cracking of sulfideresistant casing stell PllOSS were studied. The results show that the corrosion rate of PllOSS increased in the first and then decreased with the increase of Cl- concentration, the corrosion rate reached the maximum when the Cl- concentration was 50 000 mg/L; PllOSS did not ethibit cracks of sulfide stress cracking and hydrogen induced cracking, the sulfide stress cracking and hydrogen induced cracking sensitivities of PllOSS were low. The reasons were the existance of homogenious tiny tempered sorbite microstructure of PllOSS, addition of beneficial elements Cr, Mo, Ti, Nb and V and low content of harmful elements of S and P.