某304不锈钢管道泄漏的失效分析

Analysis of Leakage Failure of a Type 304 Stainless Steel Tube

某氟化工企业304不锈钢管道在运行三年半后发生泄漏失效。通过直读光谱仪、光学显微镜、扫描电镜和X射线衍射仪等对失效部位材料的化学成分、显微组织、腐蚀形貌及腐蚀产物进行了分析。结果表明:该304不锈钢管道的失效主要为Cl-浓缩造成的点蚀穿孔,H_2S的存在则对点蚀起到了促进作用。

Leakage failure occurred at a 304 stainless steel tube after working for three and a half years in a fluorine chemical enterprise. The chemical composition, microstructure, corrosion morphology and corrosion products of the material in failed part of 304 stainless steel tube were studied using direct reading spectrometry, optical microscopy, scanning electron microscopy and X-ray diffraction. The results show that the major failure mode was pitting corrosion and perforation due to local enrichment of Cl in the tube, and the existence of H2S promoted pitting corrosion.