铁基合金激光熔覆层的高温磨损性能

为提高40Cr钢表面耐磨性，采用预置激光熔覆法在40Cr基体表面制备Fe基涂层,利用HT-500摩擦磨损实验机测定干摩擦条件下，基体和熔覆层的摩擦因数随温度变化的规律。利用表面粗糙度轮廓仪测量磨痕的深度和宽度，SEM观察熔覆层以及磨痕的显微组织形貌，使用HV-1000型显微硬度仪检测基体和熔覆层结合部分的硬度。研究结果表明:熔覆层平均显微硬度值达到373.8HV(0.2);显著高于基体硬度198.4HV(0.2)。在干摩擦条件下，随着温度升高，磨损过程逐渐变平缓，平均摩擦因数降低，磨损率增加，耐磨性下降;在350~400 ℃之间，熔覆层磨损性能优于基体。

Wear performance of Fe-based alloy strengthened by laser cladding under high temperature

In order to increase the wear life of 40Cr steel, preset laser cladding techniques were adopted with Fe-based alloy powders which were obtained on the 40Cr steel substrate. Wear tests were carried out with HT-500 wear tester to determine the rule of friction coefficient varying with temperature under dry friction condition. Moreover, the depth and width of wear scars were measured by surface roughness profiler. The micrographs of wear scar on cladding coating were scanned by SEM. The microhardness of both cladding coating and substrate were measured by HV-1000 microhardness instrument. As the tests show, under dry sliding condition, with the increase of temperature and wear time, the wear course became stable. The average friction coefficient reduced,the wear rate rose, the wear resistance