热处理参数对高碳钢低周疲劳裂纹扩展行为的影响

研究了高碳钢（1.0%C碳工钢；1.0%C，1.5%Cr轴承钢）经不同热处理后的疲劳裂纹扩展行为。试验结果表明：1.淬火温度、回火温度、疲劳裂纹扩展机制、二次碳化物尺寸、试样的淬硬深度等因素，均影响疲劳裂纹扩展速率da/dN。2.疲劳裂纹的扩展临界长度a c，仅受回火温度的影响。其它因素对a c值无可见的影响。3.高温淬火并低温回火后，疲劳裂纹沿原奥氏体晶界扩展。

THE INFLUENCE OF THE PARAMETERS OF HEAT TREATMENT ON THE CRACK PROPAGATION OF LOW-CYCLE FATIGUE IN HIGH CARBON STEELS

The crack propagation of low-cycle fatigue in high carbon steels(1.00o C carbon steel and 1.0%`C, 1.5%Cr bearing steel), which are treated at various temperatures, has been studied. It is showed that:1.The rate of crack propagation da/Dn is affected by following parameters; quenching temperature, tempering temperatures mechanism of crack propagation, carbide size and depth of hardening.2.The critical length of fatigue crack a. is only affected by tempering temperature, and is not effected by other parameters.3.If the steels are treated by a high temperature queuching with low tempering; the fatigue crack propagates along the boundaries of prior austenite grains.