Failure Analysis of 304L Stainless Steel Pipe

Some 304L stainless steel pipes were welded and experienced pressure test. After being placed for a period of time, some of steel pipes were corroded and perforated. In order to find out the failure causes of the steel pipes, macroscopic and microscopic observations were carried out to one of the failed pipes. Moreover its microstructure, inclusions, chemical composition, corrosion product composition and hardness were analyzed. The results show that the reasons for corrosion perforation of the 304L stainless steel pipe were the exceeding standard requirements of carbon content in the base metal and the weld, the high level of harmful inclusions and the high concentration of Cl ion in the test water. Improving measures were proposed to prevent such accident.