304不锈钢输送管线穿孔泄漏原因OA

Before the 304 stainless steel water supply pipeline of a petrochemical company was restarted after 3 years of storage,the staff found that perforation and leakage occurred in many elbows during the hydraulic test.The leakage causes of the pipeline were analyzed by means of macroscopic observation,chemical composition analysis,hardness and ferrite content test,metallographic examination,scanning electron microscopy and energy spectrum analysis.The results show that the steel tube without solid solution treatment had more δ-ferrite in the microstructure,which greatly reduced the pitting corrosion resistance of the material.In addition,after the completion of the preliminary hydraulic test,the accumulated water inside the pipeline was directly sealed without being drained away,and the Cl-in the accumulated water was concentrated at the bottom of the elbow,which eventually led to pitting corrosion and perforation of the pipeline during storage.