Y_(2)O_(3)对等离子堆焊WC/Ni60堆焊层组织及性能的影响

Effects of Y_(2)O_(3) on Microstructure and Properties of Plasma Surfacing WC/Ni60 Surfacing Layer

利用等离子堆焊在Q235钢板上制备镍基复合堆焊层,研究了不同含量的Y_(2)O_(3)对镍基碳化钨堆焊层组织及性能的影响。采用SEM、XRD分析了堆焊层的微观组织;使用维氏硬度计和端面高温摩擦磨损试验机对堆焊层进行了硬度和磨损性能测试。结果表明:Y_(2)O_(3)的加入促使堆焊层中碳化物规则化,以WC为核心向周围生长。堆焊层检测出主要的物相为γ-Ni(Fe)、WC、W_(2)C、M_(23)C_(6)、M_(6)C、Cr_(7)C_(3)、FeNi_(3)相。添加1.2%Y_(2)O_(3)的堆焊层维氏硬度达到最大值970 HV0.5,比未加Y_(2)O_(3)的堆焊层硬度高283 HV0.5,在高温摩擦磨损条件下磨损量最小为2.8 mg,摩擦系数为0.32,此时磨损机制为轻微的磨粒磨损。

The nickel-based composite surfacing layer was prepared on Q235 steel plate by plasma surfacing,and the effects of different contents of Y_(2)O_(3) on the microstructure and performance of the nickel-based tungsten carbide surfacing layer were studied.The microstructure of the surfacing layer was analyzed by SEM and XRD,and the hardness and wear properties of the surfacing layer were tested by Vickers hardness tester and end-face high temperature friction and wear tester.The results indicate that the addition of Y_(2)O_(3) makes carbide regularization in the surfacing layer,and it grows around with WC as the core.The main phase in the surfacing layer isγ-Ni(Fe),WC,W_(2)C,M_(23)C_(6),M_(6)C,Cr_(7)C_(3) and FeNi3 phases.The microhardness of the surfacing layer added with 1.2%Y_(2)O_(3) reaches the maximum value of 970 HV0.5,which is 283 HV0.5 higher than that of the surfacing layer without Y_(2)O_(3).Under high temperature friction and wear conditions,the minimum wear amount is 2.8 mg,and the friction coefficient is about 0.32.At this time,the wear mechanism is slight abrasive wear.