稀土(镝)对钨钼表面高速钢摩擦性能的影响

Effect of rare earth Dy on friction properties of surface high-speed steel

采用双层辉光等离子渗金属技术在Q235钢表面渗入钨、钼、镝,并进行渗碳淬火和回火以形成表面高速钢层。研究表面高速钢层的成分和显微硬度,并利用HSR-2M型高速往复摩擦磨损试验机进行摩擦磨损性能研究。结果表明:镝的加入可以提高碳钢表面钨,钼,碳元素的含量,使得表面高速钢层的表面硬度从1072 HV0.05提高到1153 HV0.05;在10 N,20 N,30 N,40 N的载荷下,钨钼镝表面稀土高速钢的平均摩擦系数分别是钨钼表面高速钢的0.98倍,0.9倍,0.77倍,1.24倍;磨损体积分别是钨钼表面高速钢的0.98倍,0.76倍,0.93倍,0.83倍;在往复干摩擦条件下,钨钼表面高速钢的磨损失效形式主要是粘着磨损;加入镝后,失效模式改变为磨粒磨损,摩擦系数降低,显示出良好的减摩性能。

W-Mo-Dy surface high-speed steel were prepared by double glow plasma surface alloying technology on Q235 steel surface and then carburizing, quenching and tempering were carried out. Composition and micro-hardness of the surface high-speed steel layer were examined, and wear-properties of the surface high-speed steel layer was studied on a HSR-2M high-speed reciprocating friction tester. The results show that Dy addition is favorable to the increase of the content of W, Mo, C, which makes the hardness of surface high-speed steel layer increase from 1072 HV0.05 to 1153 HV0.05. Under the loads of 10 N, 20 N, 30 N and 40 N, the average friction coefficient of W-Mo-Dy surface rare-earth high-speed steel is 0. 98 times, 0.9 times, 0.77 times and 1.24 times as that of W-Mo surface high-speed steel, respectively, while the wear volume loss of W-Mo-Dy surface high-speed steel is lower than that of W-Mo surface high-speed steel. Under dry reciprocating rubbing, the main failure modes of W-Mo surface high-speed steel and W-Mo-Dy surface high-speed steel are adhesive wear and abrasive wear, respectively.