采用金相显微镜、扫描电镜等方法对苯加氢系统不锈钢短节失效开裂进行了研究。结果表明, 开裂的主要原因是短节管材质中存在较严重的氮化物类夹杂, 且夹杂呈聚集或链状分布。当短节管承受拉伸应力时, 夹杂物较多位置产生应力集中, 在湿硫化氢介质作用下形成腐蚀开裂。提出了防止管件开裂的安全运行建议。

The stainless steel nipple fracture in a benzene hydrogenation pipe system was analyzed by means of metallographic microscopy and scanning electron microscopy. The results show that the main reason of the fracture was the severe nitride inclusion in the steel. With the aggregation or chain distribution of such inclusions, when the nipple were under tensile stress, stress concentration was generated on the position where the inclusion is severely distributed, under the impact of wet hydrogen sulfide stress corrosion cracking occurred. Some safety countermeasures were proposed.