Effect of H2S/CO2 partial pressure ratio on tensile properties of X80 pipeline steel

摘要

Tensile properties and fracture behavior of X80 pipeline steel exposed to corrosion environments with different pressure ratios of H2S/CO2 were investigated through slow strain rate tests. The results show that the tensile properties of X80 steel were damaged in the H2S/CO2 environments. The tensile strength and elongation to failure of X80 steel decreased significantly with the increasing H2S/CO2 partial pressure ratio. Fractography of the corroded samples exhibited mixed ductile-brittle rupture. Fractured areas with quasi-cleavage features increased as the H2S/CO2 partial pressure ratio increased. Different cracks also appeared on the steel as the H2S/CO2 partial pressure ratio increased.