俄罗斯机组汽轮机叶片断裂失效机理分析

通过化学成分、断口宏观、常温和高温拉伸性能试验、显微组织、显微硬度、断口SEM扫描电镜及EDS能谱等分析方法,对1台俄罗斯机组汽轮机第22级、第23级叶片断裂机理进行了试验研究。通过对试验数据的综合分析,认为该汽轮机第22级、第23级叶片断裂失效是在交变应力作用下的疲劳断裂;表面加工精度差引起应力集中,显微组织不佳导致叶片的抗疲劳性能下降,是造成叶片断裂失效的重要原因之一。

Analysis on Failure Mechanism of Blade Fracture of Russia-made Turbine Unit

Through analysis methods such as chemical composition analysis,tensile test under high and normal temperature, microstructure analysis,microhardness analysis,and using fracture Scanning Electron Microscope(SEM)and Electronic Microscopic Data Process System(EDS),the fracture mechanism of blades in the 22th and 23rd stages has been tested.The comprehensive analysis of the test data shows that the blade fracture failure is resulting from the effect of fatigue fracture caused by alternative stress.Rough processing surface leading to stress concentration,and the fatigue property decrease resulting from poor microscopic organization are important causes of the blade fracture failure.