制氢装置三通管开裂失效分析

Fracture Failure Analysis on Tee in Hydrogen Production Device

某石化企业制氢装置中,一材料为321不锈钢的三通管开裂,零件失效。采用金相、电镜、能谱检验和硬度测试等方法对裂纹断口进行了分析,通过应力分析、应力腐蚀环境的分析、管内流体介质的动态数值模拟,分析判断出管道上裂纹出现的机理是应力腐蚀与应力疲劳共同作用的结果。

In the middle temperature shift gas heat exchanger of the hydrogen plant of a petrochemical company, some cracks were found in the upper tube of a tee made from 321 stainless steel material, by which, the part failure was caused and the production was interrupted. These cracks were located on the straight pipe nearby the welded joint. The cracks were analyzed through metallographic, scanning electron microscope, energy spectrum detections and hardness test. The stresses analysis, the stress corrosion envi- ronment analysis, the dynamic numerical simulation analysis for fluid in the pipe was done then. The mechanism of crack is the co-action of stress corrosion and stress fatigue, where corrosion elements are ex- ist and the crack position of the pipe is impacted by fluid fluctuation.