高炉煤气能量回收透平转子二级叶片失效分析

Failure Analysis of Rotor Two-Stage Blade in Blast Furnace Gas Energy Recovery Turbine

对某公司断裂失效的高炉煤气能量回收透平转子二级叶片的宏观形貌、化学成分、硬度、断口、显微组织进行了观察和分析,以找出其失效的原因。结果表明:叶片断裂属于疲劳断裂,疲劳裂纹起始于叶片进气边;叶片断裂的原因为所用材料与常规设计材料不同,且采取的热处理工艺不当;叶片表面由颗粒冲蚀产生的大量凹坑促进了疲劳裂纹的萌生,是疲劳裂纹形成的外因。

The macrophotos,chemical composition,hardness,fracture and microstructure of the failed rotor two-stage blade in a blast furnace gas energy recovery turbine were observed and analyzed to find the failure causes.The results show that the blade fracture was fatigue fracture,and fatigue cracks initiared at the side of air inlet of the blade.The cause of the blade fracture was that the used material was different from the conventional design material and the heat treatment process was inappropriate.Blade surface was eroded by particles and thus formed a large number pits to promote the initiation of fatigure cracks,and this was the external cause of fatigure crack formation.