CL60车轮表面气体软氮化对轮轨滚动接触条件下界面黏着与表面损伤的影响

EFFECT SURFACE NITRIDING TREATMENT ON INTERFACE ADHESION AND SURFACE DAMAGE OF CL60 RAILWAY WHEELS UNDER ROLLING CONTACT CONDITIONS

在轮轨滚动接触疲劳/磨损试验台上开展了CL60车轮表面气体软氮化对轮轨滚动接触疲劳和表面磨损行为的影响研究,对比分析了车轮表面气体软氮化对轮轨表面损伤的作用机理。结果表明:表面氮化处理可使车轮表面依次形成约3μm^5μm厚均匀致密的白亮层和约20μm后的扩散层;车轮表面氮化处理后,干态下轮轨间黏着系数降低了11.7%、水态下降低了18.4%,但氮化处理仍可保持轮轨间较高的黏着系数,可以避免车轮打滑等现象的发生;渗氮处理不仅明显提高了车轮表面的耐磨性,而且也有效降低了钢轨试样的磨损,其磨损量分别减小了58.05%和10.77%。简言之,车轮渗氮处理有效降低了轮轨系统的综合磨耗,提高了车轮材料的滚动接触疲劳抗力。该方法有望应用于实际,从而有效提高轮轨系统的服役寿命、减缓重载条件下轮轨材料的损伤。

The influence of nitriding treatment on wheel/rail rolling contact fatigue and surface wear behavior of CL60 wheel was studied on JD-DRCF/M rolling contact fatigue/wear tester,the wheel surface nitriding treatment on the mechanisms of wheel/rail surface damage are compared and analyzed.The results showed that the surface nitriding treatment could form a uniform and dense white layer about 3μm^5μm thick and a diffusion layer about 20μm thick on the wheel surface.Under the wheel surface after nitriding process,the adhesive coefficient between wheel/rail was reduced by 11.7%in dry condition,and reduced by 18.4%in aqueous media,but the nitriding treatment still can keep the higher adhesive coefficient between wheel/rail system,which can prevent the occurrence of the phenomenon such as wheel-slip;Nitriding treatment not only significantly improve the wear resistance on the surface of the wheel,but also effectively reduce the wear of the rail sample,the amount of damage reduced by 58.05%and 10.77%,respectively.In short,the nitriding on wheel for wheel/rail system can effectively reduce the wear,improve the rolling contact fatigue resistance of wheel materials.The method is applied to the actual,it can effectively improve the service life of wheel/rail system,reduce the damage of wheel/rail material under the heavy-load condition.