20CrMnMo钢不同渗碳淬硬层深度的组织与应力分布

MICROSTRUCTURE AND STRESS DISTRIBUTION CHARACTERISTICS OF 20CrMnMo STEEL WITH DIFFERENT DEPTHS OF CARBURIZED LAYER

以三种渗碳淬硬层深度不同的20CrMnMo齿轮钢试样为研究对象,对其显微组织和硬度梯度进行检测,采用电化学剥层技术,借助X-350A型X射线应力仪,测量各试样深层渗碳淬硬层的残余应力及其分布,将硬度梯度与残余应力的分布进行对照,认为20CrMnMo钢渗碳淬硬层硬度小于400 HV1,均为残余压应力,之后才转换为残余拉应力,这一结果为确保齿面具有可靠的抗接触疲劳性能,合理地确定重载大模数齿轮有效硬化层深度提供技术支撑。

The microstructure and hardness gradient of 20CrMnMo gear steels with 3 different depths of carburized layer were measured. The residual stresses in depth of carburized and hardened samples were measured by using 350A X-ray stress analyzer combined with the electrochemical peeling tool. The hardness gradient was compared with the residual stress distribution. It was considered that when the hardness of carbonitriding layer of 20CrMnMo steel was less than 400 HV1, there were residual compressive stress, then it turned to residual tensile stress. It could be provided as the technical support for ensuring that the gear tooth had the reliable contact fatigue resistance and defining the effective hardening layer depth of overloaded big modulus gear more reasonable.