Evolution from near-neutral to high-pH environments susceptible to stress corrosion cracking: The role of sulfate and bicarbonate
Shidong Wang, Hamed Shirazi, Guijiang Diao, Hanan Farhat, Weixing Chen
Abstract
Stress corrosion cracking (SCC) testing was conducted on pipeline steels to investigate the transition from near-neutral to high-pH environments via solution evaporation and concentration. The study clarified the roles of sulfate and bicarbonate in enhancing crack dissolution and their impacts on SCC. In sulfate-absent concentrated solutions, intergranular branching primarily resulted from direct propagation from the crack tip, accompanied by microcrack coalescence. The presence of sulfate effectively halted further growth by inducing crack-tip blunting, thereby reducing the mechanical driving force for crack propagation . This explanation clarifies why regions ideal for SCC exhibit no reported incidents, offering strategies for SCC mitigation.