|Ni60堆焊合金由于具有良好的耐腐蚀性、抗氧化性大量应用在机械设备中，为适应其在更多工程实际中的应用。 本研究通过WC与Ni60合成粉末制备药芯焊丝，明弧堆焊制备Ni60堆焊合金，分析改变WC的添加量对堆焊合金的成分、硬度、高温耐磨性的影响，结果表明，WC能够增加堆焊层中硬质相的种类和比例，随着WC的增多，堆焊层的硬质相由WC和W2C逐渐衍生出M7C和M7C3等硬质相， 当WC含量为30%时，堆焊层的硬度最高，达到62.8HRC，此时两种高温环境中的磨损失重也最低，分别为0.0327g与0.0452g。 通过SEM分析，在较高的WC比例中，WC发生部分熔解，其周边的碳化物呈棒状垂直于WC颗粒生长；当WC含量过高时会导致气孔等缺陷的产生，高温环境中的氧化和位错的滑移作用会导致硬质相的脱落从而加剧磨粒磨损的倾向，为了获得较好的耐磨性能，WC的含量应该控制在30%左右。
|关键词: 药芯焊丝 堆焊合金 高温磨损 硬质相
|Effect of WC on microstructure and high temperature wear resistance of Ni60 surfacing alloy
Shenyang University of Technology
|Ni60 surfacing alloy is widely used in mechanical equipment due to its good corrosion resistance and oxidation resistance. In order to adapt to its application in more engineering practice. In this study, flux-cored wire was prepared by WC and Ni60 composite powder, and Ni60 surfacing alloy was prepared by open-arc surfacing. The effect of changing the amount of WC on the composition, hardness and high-temperature wear resistance of the surfacing alloy was analyzed. The results showed that WC could increase the type and proportion of hard phase in the surfacing layer. With the increase of WC, the hard phase in the surfacing layer gradually derived from WC and W2C to M7C and M7C3 and other hard phases. When the content of WC was 30%, the hardness of the surfacing layer was the highest, At 62.8HRC, the wear weight loss in the two high temperature environments is also the lowest, 0.0327g and 0.0452g respectively. According to SEM analysis, in a high proportion of WC, WC partially melted, and the carbides around it grew perpendicular to WC particles in the form of rods; When the content of WC is too high, it will lead to the formation of pores and other defects, and the oxidation in high temperature environment and the sliding effect of dislocation will lead to the falling off of hard phase, which will aggravate the tendency of abrasive wear. In order to obtain better wear resistance, the content of WC should be controlled at about 30%.
|Key words: Flux cored wire Surfacing alloy High temperature wear Hard phase