曲轴开裂原因

Crankshaft crack cause

采用宏观观察、化学成分分析、力学性能测试、微观分析等方法对某开裂曲轴进行分析。结果表明:曲轴在服役时发生润滑不良,使其与铜合金轴瓦之间相互摩擦,铜合金在摩擦高温的影响下发生异种金属渗入现象,曲轴表面形成较多填充有铜合金的微裂纹,这些裂纹成为疲劳源,最终导致曲轴疲劳开裂。

A cracked crankshaft was analyzed by means of macroscopic observation,chemical composition analysis,mechanical property test and microscopic analysis.The results show that the crankshaft had poor lubrication during service,which caused friction between the crankshaft and the copper alloy bearing bush.The phenomenon of dissimilar metal infiltration occured under the influence of high friction temperature,and many microcracks filled with copper alloy were formed on the surface of the crankshaft.These cracks became fatigue sources,which eventually led to fatigue cracking of the crankshaft.