AISI 4340钢干滑动摩擦磨损特性研究

Investigation on Friction and Wear behavior of AISI4340 Steel in Dry Sliding Condition

室温条件下,采用CFT-Ⅰ型多功能材料表面综合性能测试仪对AISI 4340钢进行了往复干摩擦磨损试验,研究了其摩擦磨损特性.采用扫描电子显微镜(SEM)和能谱仪(EDS)对磨痕和亚表层进行了观察和检测,分析了磨损表面微观形貌、亚表层塑性变形和碳氧元素含量演化.结果表明:磨损形式以磨粒磨损为主,并伴随轻微黏着磨损和剥落磨损;磨损表面分布着长度、宽度、深度不一的划痕以及鳞片状和颗粒状磨屑;磨损表面出现轻微氧化,磨屑呈现不同程度的碳富集和氧化;亚表层出现明显摩擦影响层,距表层越近,塑性变形越明显,晶界角逐渐汇聚于表面,在表面处趋于平行;往复运动导致塑性变形方向不一致,磨痕中部,塑性变形向某位置聚集.

Tribological behaviors of AISI 4340 steel have been investigated under dry sliding conditions at the room temperature of 25 ℃.The experiments were conducted on a CFT-Ⅰ multi-functional surface comprehensive performance tester.The morphology characteristics of the worn surface as well as the sub-surface were observed with a scanning electron microscope to analyze the friction and wear behavior.Induced elements transformation due to plastic deformation in sliding test has been detected by using an energy dispersive spectrometer.The results show that the main wear pattern appeared to be abrasive wear with mild adhesive wear and delamination.Various length,width and depth of worn tracks and the debris with different shape were detected.The worn surface showed mild oxidization and the wear debris was rich in carbon and mildly oxidized.Plastically deformed layer in the sub-surface was observed.And the degree of plastic deformation increased from subsurface to surface.Furthermore,grain boundary angles gradually converged to the worn surface and tended to be parallel to each other.The plastic deformation direction changed on account of the reciprocating movement,and converged at a localized zone in the middle of the worn surface.