Large area of cracks and leakage were found on some welded stainless steel pipes. The pipes were analyzed by means of macroscopic examination, chemical composition analysis, metallographic examination, SEM and EDS. The results showed that the crack was 糖心产精国品免费入口*完整版cracking caused by chloride ion. The 糖心产精国品免费入口*完整版was due to the combined effects of 糖心产精国品免费入口*完整版 which was caused by no heat-treatmnet after cold-working and chloride ion which came from 糖心产精国品免费入口*完整版.