汽轮机末级叶片断裂原因分析

对某汽轮机的叶片断口进行了描扫电镜形貌观察和元素能谱分析,结果表明该叶片是疲劳腐蚀失效。叶片是由于疲劳腐蚀产生微裂纹,在交变应力和氯离子作用下加速裂纹扩展,造成最终断裂,引起腐蚀的原因主要是蒸汽中存有氯、氧等介质。

Fracture analysis of turbine last stage vane

The paper states that the fraeture of turbine rathe iS caused by failure due to fatigue corrosion by means of topography and spectroscopy analysis of element with scanning electronic microscope. The crack is oceurred on vane due to fatigue corrosion, the crack Propagation rate speeds up under the action of alternating stress and chloride ion, in the end resulting in fi＇aeture. Herein it is proved that the medium contained in steam such as chloride, oxygen and so on is the main reagon for corrosion happened.