Effect of tempering temperature at high temperature zone on sulfide stress cracking behavior for casing steel

Abstract

Three tempering temperatures at high temperature zone (690 °C, 700 °C and 710 °C) are selected into the quenching-and-tempering processes and performed on the rolled Cr-Mo steel to develop API-5CT-C110 casing steels. Effect of tempering temperature on sulfide stress cracking (SSC) behavior is quantitatively evaluated and further explored by characterizing the microstructure and crystallography. The results show that the strength of steel decreases with tempering temperature, but the SSC susceptibility is reversely varied. EBSD analysis indicates that the steel tempered at lower temperature (690 °C) generates more grains with high Taylor factors, which are difficult to yield, leading to the increasing of dislocation density and more susceptible to SSC.