接触载荷对钢丝微动磨损行为影响的研究

Effect of Contact Load on the Fretting Wear Behavior of Steel Wire

以6×19点接触式提升钢丝绳为研究对象,在自制的微动摩擦磨损试验机上开展钢丝微动磨损的实验研究,考察在不同接触载荷下钢丝的微动磨损行为,采用S-3000N型扫描电镜观察钢丝的磨损形貌并分析其微动损伤机理.结果表明:在接触载荷为9～29 N范围内,微动摩擦力(Ft)-位移幅值(D)曲线随循环周次的变化表明钢丝运行于混合区,并随着接触载荷的增加,钢丝间接触应力增加;在微动磨损初期钢丝间的摩擦系数均较低,之后逐渐增加并趋于稳定;其稳定摩擦系数随着钢丝间接触载荷的增加而降低,接触载荷为9 N时的摩擦系数最大,约为1.25,而29 N的摩擦系数约为0.57;钢丝间的接触载荷增加,钢丝表面接触疲劳的几率增大,出现磨屑疲劳脱落的痕迹和疲劳微裂纹,其损伤机制主要表现为磨粒磨损、疲劳磨损和摩擦氧化.

The 6×19 point contact rope was taken as an example to investigate the fretting wear behavior of the hoisting rope.Thus the effect of the contact load on the fretting wear behavior was examined.Furthermore,the morphologies of the fretted steel wire surfaces were observed on the S-3000N scanning electron microscope.The results showed that the fretting behavior of the fretted steel wire was in the mixed fretting regime from 9 to 29 N based on the evolution of the friction force（Ft）-amplitude（D） curve of steel wire versus the fretting cycles,and the contact stress increased with the increasing of contact load.The friction coefficient was low at the beginning of fretting wear,and then increased gradually until to stabilize in the latter.It was found that the friction coefficient decreased with the increasing of the contact load.The friction coefficients were the highest at 9 N,and the lowest at 29 N.Moreover,as the contact load increased,the probability of contact fatigue on the wire surface increased.As a result,the wear trace appeared debris detached and micro-cracks due to fatigue.Abrasive wear,fatigue wear and tribo-oxidation were the main wear mechanisms.