中文摘要：

在球-平面接触条件下,研究LZ50车轴钢在不同法向载荷水平（50-150 N）和位移幅值（2-40μm）下的微动磨损行为。在分析微动动力学特性的同时,结合扫描电子显微镜与电子能谱仪对磨斑进行微观分析。结果表明：外加法向载荷和位移幅值强烈地影响LZ50车轴钢的微动运行区域;摩擦系数在不同微动运行区域随循环次数的变化趋势不相同。研究建立了LZ50车轴钢的运行工况微动图,其微动磨损呈现3个运行区域：部分滑移区磨斑呈环状结构,磨损轻微;混合区磨损相对严重,磨斑有塑性流动特征,有磨屑生成且能观察到犁沟,磨损机制主要是塑性变形、磨粒磨损、氧化磨损和剥层;滑移区的磨损最为严重,接触区有厚的磨屑层、大量磨屑颗粒的剥落和明显的犁沟,其磨损机制主要是磨粒磨损、氧化磨损和剥层。

英文摘要：

The fretting wear behaviors of LZ50 steel in contact configuration of ball-on-flat were carried out under varied normal loads（50~150 N） and displacement amplitudes（2~40 μm）.Dynamic analyses in combination with microscopic examinations through the means of the scan electric microscope（SEM） and energy dispersive X-ray spectroscope（EDX） are performed.The experimental results show as follows： The fretting regimes of the LZ50 steel are strongly dependent upon the imposed normal loads and displacement amplitudes;the variations of the friction coefficient in the different fretting regimes are quite different.The running condition fretting map of LZ50 steel was built up,and the dynamic process of fretting wear might be outlined as three running regimes.In the partial slip regime,the fretting scars present a typical morphology of annularity and present slight damages.In the mixed fretting regime,the traces of ploughing and plastic deformation flow can be observed on the fretting scars,and debris generation between the contact interfaces and severer degradation are visible.The wear mechanism during this regime is the combination of the plastic deformation,abrasive wear,oxidative wear and delamination.A thicker debris layer covers in the contact zone in the scar under the condition of gross slip.And the detachment of particles and ploughing are the main phenomena in the slip regime.Therefore,the severe degradation in the slip regime presents the main wear mechanisms of abrasive wear,oxidative wear and delamination.