Stress corrosion cracking behavior on carbon steel under the synergistic effect of chloride and bicarbonate ions in alternating wet-dry environment.

The stress corrosion cracking mechanism of X80 carbon steel under the combined actions of chloride and bicarbonate ions in alternating wet-dry environment was investigated by performing slow strain rate tensile test and in-situ electrochemical detection during the SCC process under constant load. The results showed that the oxidation and reduction reaction cycle of iron oxide during wet-dry cycle would accelerate the corrosion process. The pitting under the corrosion product layer at high concentrations of chloride and bicarbonate was the origin of SCC under the action of stress concentration, which made steel display high SCC susceptibility. • The interaction of chloride and bicarbonate on corrosion was explored. • In-situ electrochemical testing was used in the SCC process. • SCC mechanism of X80 steel in alternating wet-dry was clarified. [ABSTRACT FROM AUTHOR]