Role of Thiosulfate in the Corrosion of Steels: A Review

Thiosulfate salts have been known to be dangerous corrosion promoters for over 30 y, when present under typical service conditions. This paper reviews the role of thiosulfate anion in causing localized corrosion and/or stress corrosion cracking of steels. Electrochemical and mechanical aspects associated with the pitting and stress corrosion cracking of steels in thio-sulfate-containing environments are thoroughly discussed and reviewed. In particular, results from the research studies relevant to pulp and paper, oil and gas, and nuclear industries, where thiosulfate ion is known to be present advertently or inadvertently, have been analyzed.