Bending fatigue tests of carburized gear in high cycle fatigue life regime were performed under stress ratio of 0.04. All the crack sources of the broken teeth are originated from the stress concentration on the surface of teeth root. By considering the effects of surface residual stress, notch effect, stress gradient and crack size, the predicted initiation life model of carburized gear is established by dislocation energy method. Meanwhile, based on the Paris Equation, the crack length a corresponding to fracture toughness and real crack propagation path, the predicted growth life model of carburized gear can be established. Finally, based on the behaviors of crack initiation and propagation, the whole life prediction model of carburized gear can be constructed, and the prediction accuracy of the model is within three times of the test life, which can be used to predict the bending fatigue life of carburized gear.

渗碳齿轮在高周疲劳寿命状态下的弯曲疲劳试验在应力比为 0.04 下进行。断齿的所有裂纹源均源于齿根表面的应力集中。综合考虑表面残余应力、缺口效应、应力梯度和裂纹尺寸的影响，采用位错能法建立渗碳齿轮初始寿命预测模型。同时，根据巴黎方程，裂纹长度a对应断裂韧性和实际裂纹扩展路径，可以建立渗碳齿轮的预测生长寿命模型。最后，基于裂纹萌生和扩展行为，构建渗碳齿轮全寿命预测模型，模型预测精度在试验寿命的3倍以内，可用于预测弯曲疲劳寿命渗碳齿轮。