42CrMo钢火焰喷涂Ni60/WC涂层的电接触强化研究  

Electric Contact Strengthening of Flame Spraying Ni60/WC Coating on the Surface of 42CrMo Steel

作　　者：李俊[1] 范金辉[1] 徐梦廓[1] 朱世根[1] 

机构地区：[1]东华大学机械学院纺织装备教育与研究中心,上海201620

出　　处：《表面技术》2016年第9期65-70,共6页Surface Technology

基　　金：上海市重点学科建设资助项目(B602)~~

摘　　要：目的研究电接触强化对氧乙炔火焰喷涂后42CrMo基体表面涂层组织与性能的影响,以改善涂层与基体之间的结合强度,提升基体表面性能。方法利用氧乙炔火焰喷涂,在基体表面制备Ni60/WC涂层,再进行电接触强化。通过金相显微镜、扫描电镜及能谱分析等方式,对涂层及基体进行显微组织观察和物相分析,利用维氏显微硬度仪测量涂层到基体的硬度分布,并对电接触强化前后的数据进行对比分析。结果在热喷涂涂层厚度一定的情况下,经15 k A电流强度电接触强化后,涂层的致密性显著提高,孔隙明显减少,与基体接触部分的界面缝隙消失,结合方式发生改变。涂层硬度均匀性改善明显,维氏硬度显著提高,由原来400HV提升至720HV左右。涂层内部形成了Cr元素聚集区,W元素扩散明显,形成了合金元素碳化物,对涂层起到弥散强化作用。结论电接触强化能显著提高涂层性能与质量,改变涂层与基体之间的结合方式。Objective To study the effect of electric contact strengthening （ECS） on microstructure and properties of 42CrMo substrate surface coating after oxyacetylene flame spraying so as to improve the bonding strength between coating and substrate and the surface properties of the substrate. Methods Ni60/WC coating was prepared on the surface of 42CrMo steel by oxyacetylene flame spraying, and the coating was strengthened by ECS technology. The microstructure of coating and substrate was observed and analyzed by metallographic microscope, SEM and EDS. The hardness from coating surface to substrate was measured by vickers hardness tester. Data got before and after ECS were analyzed. Results With the flame spraying coating thickness controlled, dense coating got raised and the pore reduced significantly while the interface between the substrate and coating disappeared because of the binding mode changing after ECS by 15 kA current strength. After strengthening by ECS technology, the hardness uniformity was greatly improved and the Vickers hardness was improved from 400HV to 720HV. Dispersion strengthening appeared as the carbide phase was formed due to the Cr element＇s gathering and W element＇s diffusion. Conclusion The ECS technology can upgrade the per- formance and quality of the coating and change the binding mode of the interface.

关 键 词：氧乙炔火焰喷涂 电接触强化 Ni60/WC涂层 界面结合强度 复合表面强化 42Cr MO 

分 类 号：TG174.442[金属学及工艺—金属表面处理]