激光重熔对42CrMo钢渗硼层组织和性能的影响

Effect of laser remelting on microstructure and properties of boronized layer of 42CrMo steel

减少渗硼层表面存在的疏松组织和孔洞,对42CrMo钢渗硼层进行激光重熔处理。通过金相显微镜分析了激光重熔前后渗硼层的组织形貌和物相变化,用维氏硬度计、摩擦磨损试验机和电化学工作站进行激光重熔前后硬度、摩擦性能和腐蚀性能的测试。试验结果表明:渗硼层经过激光重熔后,重熔区形成了致密细小的共晶硼化物,疏松孔洞消失,硬化区扩大,表面与基体的结合力增强,硬度梯度大幅降低,腐蚀性能也随之改善,摩擦机制的改变使得摩擦系数显著减小,磨损质量比渗硼件降低61%。

In order to reduce the porosity of the boronized layer,the surface of the boronized layer of 42CrMo steel is treated by laser remelting. The surface morphologies and phase of laser remelted layer and boronized layer were analyzed by metallographic microscope. The hardness,friction coefficient and corrosion resistance of the hardened surface before and after laser remelting were tested by using a hardness tester,a friction and wear tester and an electrochemical workstation. The test results show that the compact eutectic boride is formed in the remelting zone,and the porosity and porosity of the boride are disappeared and hardened zone expand. The remelting layer obtain lower hardness gradient,higher bonding strength and better friction and corrosion resistance. With the change of friction mechanism,the coefficient of friction is obviously decreased,and the wear quality is reduced by 61%.