Ductile intergranular fracture of PM 304 stainless steel

Acoustic emission (AE) response of a sensitized 304 stainless steel during intergranular corrosion (IGC) and stress corrosion cracking (SCC) has been detected. Active dissolution and IGC can generate AE signals but the AE activity and amplitude are relatively low. The number of AE signals increases smoothly during the SCC process. The fracture mode is mixed intergranular and transgranular. Both plastic deformation and crack propagation are acoustic emissive during the transgranular cracking while during the intergranular cracking only plastic deformation in the vicinity of the crack tip contributes to the AE signals.