Mechanisms and Preventing Methods of Premature Corrosion Cracking of 316L Stainless Steel Short Connection

Macro characteristics, micro morphology and microstructure of the corrosion cracks of a 316L stainless steel short connection in the environment of salt chemical industry were analyzed. The influences of brine parameters and manufacturing processes on the corrosion of 316L stainless steel short connection were investigated. The results show that the premature failure of the short connection was due to pitting and stress corrosion cracking (SCC). The pitting of short connection was mainly caused by high temperature and high Cl^- concentration of brine, and the combined action of welding residual stress and crimping stress promoted SCC of the short connection. Adopting casting instead of welding and appropriately increasing the content of molybdenum were helpful to extend the service life of the short connection.