轮缘固体润滑剂对轮轨减摩及损伤性能影响

Effect of wheel flange solid lubricants on friction reduction and damage performance of wheel/rail

用MMS-2A滚动摩擦磨损试验机完成试验工作,对比干态和3种不同固体润滑剂作用工况,分析干态和3种不同固体润滑剂作用后的轮轨摩擦性能和固体润滑剂的有效作用时间,探究固体润滑剂对轮轨摩擦性能的影响;分析不同工况下轮轨表面磨损量和表面裂纹,同时对裂纹的长度、角度、深度进行统计,分析固体润滑剂作用对轮轨损伤性能影响。结果表明:固体润滑剂具备减摩润滑作用,其中1号效果最佳,将干态下的摩擦系数0.5降低到0.2左右;固体润滑剂通过降低接触界面的摩擦系数减小轮轨界面的切向摩擦力,降低轮轨表面的磨损量,其中固体润滑剂1降低车轮和钢轨的磨损量最大,分别降低95.3%和97.1%;固体润滑剂主要通过抑制疲劳裂纹的长度来抑制轮轨疲劳裂纹的生长和扩展,通过正应力挤压作用使轮轨表面疲劳裂纹开口紧闭,缓解裂纹根部分支现象,有效抑制轮轨疲劳裂纹生长与扩展行为.

Friction and damage tests under the conditions of dry and three different solid friction lubricants were carried out on the MMS-2A rolling friction wear apparatus to analyze friction property and study the effect of wheel-rail friction performance under different solid friction lubricants and the effective time.The wear and surface cracks of the wheel/rail under different conditions were analyzed,the length,angle,and depth of the crack were recorded to analyze the effect of wheel-rail damage performance under different solid friction lubricants.Results show that the solid friction lubricant could modify the friction of the wheel/rail effectively,and lubricant 1 had the best effect,which decreased the coefficient of friction from 0.5 to 0.2.The solid lubricants reduced the tangential friction of the wheel/rail interface and the wear of the wheel/rail surface by reducing the friction coefficient of the contact interface.Further,the solid lubricant 1 reduced the wear volume of the wheel and the rail to the maximum(95.3%and 97.1%respectively)to improve the wear resistance of the wheel/rail material.All three lubricants could inhibit the growth and expansion of the wheel/rail fatigue crack by suppressing the length of the fatigue crack.The fatigue crack opening of the wheel/rail surface was closed through the normal stress extrusion.Solid lubricant relieved the branch of the cracked roots,and suppressed the fatigue crack growth and expansion behavior of wheel and rail effectively.