CBN砂轮对GCr15钢的磨削硬化试验研究

Experimental study on grind-hardening of GCr15 steel with CBN grinding wheel

为了对磨削硬化加工提供更多的理论依据,采用CBN砂轮对GCr15钢进行了磨削硬化试验,对磨削硬化加工过程中磨削组织的变化,以及磨削参数对磨削硬化层的硬度及其分布的影响进行了分析与研究。采用暗场显微镜观测了磨削前后GCr15钢的组织变化,并分析了组织变化的原因;采用显微维氏硬度计分析了硬化层硬度均匀性以及产生硬度不均匀性的原因;通过磨削硬化试验组研究了磨削参数对硬化层硬度的影响,并从磨削热的角度分析了产生此类影响的原因。研究结果表明:硬化层深度为0.12 mm,工件微观组织的转变是影响磨削过程中硬化层硬度均匀性的主要因素,适当提升磨削深度和工件进给速度可以获得更高的硬化层硬度,加快工件的冷却速率也可以提升硬化层的硬度。

In order to provide more theoretical basis for the grind-hardening process,CBN grinding wheel was used for the grind-hardening test of GCr15 steel,the changes of the grinding organization during the grind-hardening process and the influence of the grinding parameters on the hardness and distribution of the hardened layer were analyzed and studied.The dark-field microscope was used to observe the microstructure changes of GCr15 steel before and after grinding,and the reasons for the microstructure changes were analyzed.The micro-Vickers hardness tester was used to analyze the hardness uniformity of the hardened layer and the causes of the hardness nonuniformity.The influence of the grinding parameters on the hardness of the hardened layer was studied by the grind-hardening test group,and the causes of such effects were analyzed from the perspective of grinding heat.The results indicate that the depth of the hardened layer is 0.12 mm,the transformation of the microstructure of the workpiece is the main factor affecting the hardness uniformity of the hardened layer during the grinding process.Properly increasing the grinding depth and workpiece feed rate can achieve higher hardness of the hardened layer,and increasing the cooling rate of the workpiece can also increase the hardness of the hardened layer.