Cause Analysis of Corrosion of Sylvite Evaporators Made of 2507 Duplex Stainless Steel

According to the case study of evaporators used in two projects of an institute,the reasons for corrosion cracking of 2507 duplex stainless steel evaporators were analyzed from the operational environment and manufacturing process.Furthermore,the ways to avoid the corrosion of duplex stainless steel evaporators were investigated from design,manufacturing and operation.The results show that both operational environment and manufacturing process have great influences on the corrosion of duplex stainless steel evaporators.Stress corrosion cracking occurs easily when there are welding flaws,stress concentration because of assemble residual stress on the evaporators,or they work in the conditions of strong acid,high temperature and solution with high concentration of Cl^-.