激光熔覆HSS涂层滚滑动摩擦磨损及热疲劳损伤研究

Study of rolling-sliding friction and wear and thermal fatigue damage of laser-clad HSS coating

针对再制造轧辊使用过程中受高压高温作用,轧件易发生复杂的失效行为,文章采用激光熔覆技术在球墨铸铁芯材上制备M4高速钢(high-speed steel,HSS)涂层,利用高温滚滑动摩擦磨损与热疲劳试验机研究HSS涂层的摩擦磨损及热疲劳性能。结果表明:HSS涂层显微组织主要为马氏体、少量残留奥氏体和合金碳化物,涂层维氏硬度为823 HV 0.5,具有良好的耐磨性、耐热性。在滚滑动摩擦磨损形式下,随着表面接触温度的升高,涂层磨损机制发生改变,磨损量逐渐降低。440℃时表现为疲劳磨损和轻微氧化磨损,525℃时表现为氧化磨损和疲劳磨损,580℃时以氧化磨损为主。

In response to the complex failure behavior of the rolled parts during the use of remanufacturing rollers under high pressure and high temperature,this paper used laser cladding technology to prepare M4 high-speed steel(HSS)coating on ductile iron core material.The friction,wear and thermal fatigue properties of the HSS coating were studied using a high-temperature rolling-sliding friction,wear and thermal fatigue testing machine.The results show that the microstructure of the HSS coating is mainly martensite,a small amount of residual austenite,and alloy carbides.The coating has a microhardness of 823 HV 0.5,and has good wear resistance and heat resistance.In the form of rolling-sliding friction and wear,as the surface contact temperature increases,the wear mechanism of the coating changes and the wear amount gradually decreases.At 440℃,it exhibits fatigue wear and slight oxidation wear,at 525℃,it exhibits oxidation wear and fatigue wear,and at 580℃,it mainly exhibits oxidation wear.