Study on Prediction and Monitoring Technique of Failure of Gear Teeth by Means of AE Method

研究了SCM415表面硬化、S45C正火、两种ADI [ADI 1：T = 875 ℃，TI = 375 ℃，ADI 2：T = 875 ℃，TI = 235 ℃，（T：等温处理温度，TI：235 ℃）]弯曲疲劳过程中的声发射信号、声发射累积事件计数、声发射事件计数率、声发射累积能量计数、声发射能量率、声发射幅值、声发射信号频谱及裂纹扩展<LAMBDA><LAMBDA><LAMBDA>情况。等温转变温度）]和SACM 645离子渗氮齿轮齿在不同齿面载荷下的摩擦磨损性能。确定了弯曲疲劳过程中声发射参数与疲劳裂纹扩展的关系以及齿轮材料和轮齿载荷对声发射特性的影响。为用声发射方法预测和诊断轮齿弯曲疲劳失效提供了基础数据，主要研究结果如下：1. AE累积事件计数 ...更多信息 t和AE累积能量计数在齿轮弯曲疲劳过程中的齿轮齿的裂纹萌生前显着增加，并成为几乎恒定的裂纹扩展的情况下，表面硬化和ADI 1齿轮。在离子渗氮齿轮的情况下，这些AE参数在疲劳过程中的变化表现出相同的趋势的情况下的表面硬化齿轮，但增加率是相当小的情况下的表面硬化齿轮。在ADI 2齿轮的情况下，这些AE参数增加后，裂纹萌生。在正火齿轮的情况下，这些AE参数的变化与裂纹萌生几乎不能观察到。因此，使用这些AE参数预测裂纹萌生在表面硬化、ADI 1和离子氮化齿轮的情况下是可能的，但在ADI 2和正火齿轮的情况下是困难的。2.渗碳齿轮、ADI 1齿轮和离子渗氮齿轮弯曲疲劳过程中的声发射幅值在疲劳初期较小，在裂纹萌生前增大，在裂纹扩展过程中减小，在断齿前增大。在ADI2齿轮的情况下，AE振幅在裂纹萌生之后变得更大。齿轮正火后，几乎观察不到大幅度的声发射信号。3.在弯曲疲劳过程中，离子渗氮、表面硬化、奥贝球铁和正火齿轮齿的声发射信号最大幅值依次减小。少

Research was conducted on AE signals, AE cumulative event count, AE event count rate, AE cumulative energy count, AE energy rate, AE amplitude, frequency spectra of AE signals and crack propagation in the bending fatigue process of SCM415 case-hardened, S45C normalized, two kinds of ADI [astempered ductile iron, ADI1 : T_<LAMBDA> = 875ﾟC,T_I = 375ﾟC,ADI2 : T_<LAMBDA> = 875ﾟC,T_I = 235ﾟC,(T_<LAMBDA> : temperature of austemper treatment, T_I : temperature of isothermal transformation)] and SACM645 ion-nitrided gear teeth under different tooth loads. The relationship between the AE parameters and the fatigue crack propagation as well as the effects of the gear material and the tooth load on the AE characteristics in the bending fatigue process were determined. Basic data were obtained for the prediction and the diagnosis of bending fatigue failure of the gear tooth by means of AE method.The main results obtained from this investigation are summarized as follows.1. AE cumulative event coun … More t and AE cumulative energy count in the bending fatigue process of gear teeth increase markedly just before the crack initiation and become almost constant in the crack growth in the cases of the case-hardened and the ADI1 gear. In the case of the ion-nitrided gear, the change of these AE parameters in the fatigue process shows the same tendency as the case of the case-hardened gear, but the increasing rate is considerably smaller than in the case of the case-hardened gear. In the case of the ADI2 gear, these AE parameters increase after the crack initiation. In the case of the normalized gear, the changes of these AE parameters with the crack initiation can hardly be observed. Hence, the prediction of the crack initiation using these AE parameters is possible in the cases of the case-hardened, the ADI1 and the ion-nitrided gear, but difficult in the cases of the ADI2 and the normalized gear. 2.AE amplitudes in the bending fatigue process of the case-hardened, the ADI1 and the ion-nitrided gear are small in the early stage of the fatigue process, become larger just before the crack initiation, smaller in the crack growth and larger just before the tooth breakage. In the case of the ADI2 gear, AE amplitude becomes larger after the crack initiation. In the case of the normalized gear, AE signals with large amplitude can not be almost observed. 3. Maximum amplitudes of AE signals in the bending fatigue process of the ion-nitrided, the case-hardened, the ADI and the normalized gear tooth become smaller in the order mentioned. Less