对LZ50车轴钢表面进行离子氮化/激光淬火复合处理。在对复合改性层进行表征的基础上,对比研究了复合改性层和基体在干态不同角位移幅值下的扭动微动磨损行为。结果表明,LZ50钢经过复合处理后在表面层形成了均匀分布的针状马氏体;复合处理改变了LZ50钢的扭动微动运行区域,使得混合区减小,滑移区向小角位移方向移动;复合改性层的摩擦扭矩和耗散能在整个运行区域都低于LZ50钢,其磨损程度明显降低,在部分滑移区损伤轻微,在混合区和滑移区,损伤主要表现为剥层、磨粒磨损和氧化磨损。总之,复合改性层具有良好的抗磨减摩特性。
An ion nitriding /laser hardening duplex modified treatment has been prepared on LZ50 steel surface. Base on the characterizations of the duplex modified layers,the torsional fretting wear tests of the duplex modified layers and LZ50steel were comparatively carried out in dry condition under different torsional angular displacement amplitudes. The results indicated that some evenly distributed acicular martensites were formed in the surface layer of LZ50 steel after the duplex modification processes. The fretting regimes of the duplex layers have been changed,i. e. the range of the mixed fretting regime was diminished,and the slip regime shifted to the direction of smaller angular displacement amplitude.The friction torques and the friction dissipated energy of the duplex modified layers were lower than that of the substrate in the all running regimes. To compare with the substrate,the wear of material reduced greatly for the duplex modified layers. The damage in the partial slip regime was slight,but in the mixed and slip regimes the damage mechanisms of the duplex modified layers were mainly delamination,abrasive wear and oxidative wear. In sum,the ion nitriding /laser hardening duplex modified layers presented well characteristics of anti-wear and anti-friction.