Cracking Analysis of External Pressure Stainless Steel Bellows Expansion-joint

External pressure axial type bellows expansion joint of austenitic stainless steel cracked after using for short time. The cracking reason was analyzed by means of chemical composition analysis, metallographic examination and fracture analysis. The results showed that superheated steam of working medium in the expansion-joint contained corrosive chloride ions, and the expansion-joint was affected by tensile stress, which resulted in stress corrosion cracking.