Effect of Ferrite content and weld heat input on the room temperature stress corrosion cracking resistance of austenitic clad metals

摘要

AbstractAustenitic stainless steel claddings with different ferrite contents (2, 4, 10, 12 FN) were obtained by the submerged are welding (SAW) strip cladding process. In order to study the effect of heat input the claddings were removed from the base plate and TIG remelted. Stress corrosion cracking (SCC) tests were carried out with notched tensile specimens in 5 N H2SO4+ 0.5 N NaCl at room temperature. A net‐section stress required to break the specimen in 100 hours was taken as a criterion of relative SCC susceptibility. The effect of cathodic protection was studied by coupling the specimens with zinc.The results showed that increasing ferrite content decreases SCC resistance. TIG remelted material exhibited better SCC resistance than the SAW specimens. Cathodic protection improves the SCC resistance of all the specimens. Cracking was found to be due to strain‐assisted ferrite dissolution and SCC in austenite. SCC in austenite was due to tunnelling mechan