基于纳米压痕技术的齿根渗碳层力学特征表征

Characterization on Mechanical Properties of Carburized Layer at Gear Root Based on Nano-Indentation Technology

18Cr2Ni4WA齿轮齿根的渗碳层具有不同于基体的力学特性,准确表征其力学特性对于研究齿轮齿根的裂纹萌生和疲劳性能至关重要。将纳米压痕技术作为渗碳层局部力学特性表征的试验手段,针对渗碳层开展纳米压痕试验,结合有限元仿真,根据不同本构参数组合下的载荷–位移曲线的曲率、残余深度、塑性功与总功之比3项参数预测的综合误差,确定18Cr2Ni4WA齿轮齿根渗碳层的本构参数。试验验证结果表明,由纳米压痕试验得到的载荷–位移曲线能够可靠地反映渗碳层的力学行为。

The carburized layer at 18Cr2Ni4WA steel gear root has mechanical behavior different from the substrate.Its accurate characterization is important for the analysis on the crack initiation and fatigue properties of the gear root.The nano-indentation test is taken as the test measure for the characterization of the local mechanical behavior in the carburized layer.Nano-indentation tests are carried out within the carburized layer.Thefinite element simulations of nano-indentation tests with different sets of constitutive model parameters combination are performed.Based on the simulated and the experimental load-displacement curves,the combined prediction errors of curvature,residual depth and the ratio of plastic deformation work to total deformation work are calculated.In result,the constitutive model parameters are defined for the carburized layer.It is verified that the constitutive model derived by this method can reflect the mechanical behavior of the carburized layer.