曲轴圆角残余应力的XRD试验研究

Experimental Study on Residual Stresses of Crankshaft Chamfer with XRD

利用X射线衍射法对曲轴圆角处残余应力进行了测试,分析了曲轴在机械喷丸、滚压、等温淬火等3种工艺下残余应力的分布规律及其形成机理,并对其进行了疲劳寿命对比试验。结果表明,机械加工后曲轴圆角处残余应力处于拉压交错状态,是影响曲轴疲劳寿命的主要因素;机械滚压和等温淬火工艺改善了残余应力的分布,使圆角残余拉应力均变为压应力,基本上满足曲轴5×106次疲劳试验的要求;喷丸工艺有效地改善了圆角与曲柄连接处残余压应力的分布状态,但增大了圆角与连杆接合处拉应力,其疲劳寿命为2.5×106次。

Residual stresses of crankshaft chamfer were measured with X-ray diffraction(XRD),and the distributions of residual stress and its forming mechanisms by mechanical peening,mechanical rolling and isothermal quenching were analyzed.The comparison tests of fatigue life were made.Experimental results showed that,residual stresses of crankshaft chamfer by machining were in the form of tensile-compressive status,which is the main factor to affect fatigue life of crankshaft chamfer.The crafts like mechanical rolli...