镍基合金等离子堆焊层的显微组织及摩擦磨损性能

Microstructure and Friction and Wear Properties of Plasma Surfacing Layer of Ni-based Alloy

采用等离子弧堆焊技术在1Cr18Ni9Ti不锈钢表面堆焊Ni50A镍基合金粉,研究不同焊接电流下堆焊层的显微组织、硬度及摩擦磨损性能。结果表明:堆焊层主要由γ-Ni组成,此外还存在CrB、M23(C,B)6、Cr7C3、Cr5B3、Ni3Si、Ni3B析出相;随着焊接电流的增大,堆焊层组织呈现不同的形态,160A电流下的组织最细小均匀,呈小花状及细小颗粒状,其硬度最高,为680HV耐磨性最好;堆焊层的磨损量均随着磨损时间的延长逐渐增加,190A电流下堆焊层的磨损量最大;堆焊层的磨损机制主要为粘着磨损,并伴随有磨粒磨损,后期出现氧化磨损。

The Ni50ANi based alloy powders were deposited on the surface of 1Cr18Ni9Ti stainless steer by plasma arc surfacing technology, and the microstructure, microhardness and friction and wear properties of the surfacing layer at different welding currents were studied. The results show that the surfacing layer mainly consisted of ）,-Ni and precipitates such as CrB、M23（C,B）6、Cr7C3、Cr5B3、Ni3Si、and Ni3B. The morphology of surfacing layer varied with the increase of welding current. When the welding current was 160 A, the microstructnre was floret-like and granule-like and the surfacing layer had the highest microhardness of 680 HV, and its wear resistance was the best. The wear quantity of the surfacing layer increased with the increase of wear time, and the wear quantity was the largest when the current was 190 A. Wear mechanism of the surfacing layer was mainly adhesive and accompanied by mild abrasive and oxidative wear appearing in later stage