Stress Corrosion Cracking Analysis for Manual Valves and Seal Assemblies Wrongly Degreased with Tetrachloroethylene

RIC manual valves and seal assemblies made of austenitic stainless steel were wrongly degreased with tetrachloroethylene by the manufacturer. Chloride ions（Cl^-） were produced during the pyrolysis of tetrachloroethylene,leading to the risk of stress corrosion cracking（SCC） due to the remaining Cl^-. The research shows that the Cr-Ni austenitic stainless steel becomes more sensitive to the stress corrosion cracking as the Cl^-content increases. Increasing temperature and oxygen（O） content can accelerate the SCC of austenitic stainless steel caused by Cl^-. After the analysis of the remaining Cl^- content in the manual valves and seal assemblies, operating temperature and oxygen content in the coolant, it is considered that the remaining Cl^- will not cause SCC during service of manual valves and seal assemblies. In addition, the pyrolysis of tetrachloroethylene under vacuum and abrasive blasting of surfaces can degrease Cl^- observably.