The paper describes the four types of stress corrosion cracking (SCC) that can affect stainless steels; chloride SCC, sulphide SCC, caustic SCC and hydrogen Induced stress cracking (HISC). The common grades of stainless steel used in industry will be considered, particularly austenitic and duplex stainless steels. Both full immersion and atmospheric exposure are considered. The factors that can affect the risk of initiation of each type of SCC are discussed, including the effect that small quantities of impurities in the fluid can have on the risk of failure. Oxidizers and reducing chemicals can affect the redox potential and can either move an alloy from or into an area of risk for SCC. The paper also discusses the factors that must be considered to reduce the risk of SCC and how this can be achieved. These include alloy selection, stress reduction and environmental modification. Some service experiences are described to illustrate each type of SCC and the solution chosen.
Roger Francis (Wed,) studied this question.