Sodium Thiosulfate Attacking Metal Surface

Question

Can anyone help why sodium thiosulfate with typical Ph of 8, being hydrophilic, creates severe corrosion on metal surfaces like steel. Does water activate the sulfur content in it? Is there anything to neutralize the sulfur? I will appreciate your help.

Answer 1

When present under typical service circumstances, thiosulfate salts have been known for more than 30 years to be harmful corrosion promoters. The role of the thiosulfate anion in causing steels to corrode locally or crack under stress is discussed in this work. Thoroughly examined and reviewed are the electrochemical and mechanical aspects of steel pitting and stress corrosion cracking in thiosulfate-containing settings. Analysis has been done in particular on the findings from studies related to the pulp and paper, oil and gas, and nuclear industries, where thiosulfate ions are known to be present either intentionally or unintentionally.