4种车轮材料与U71Mn热轧钢轨匹配特性

Matching Characteristics between Four Kinds of Wheel Steels and U71Mn Hot-Rolled Rail

为研究车轮材料对轮轨匹配行为的影响,在MMS-2A型轮轨磨损试验机上模拟研究了U71Mn热轧钢轨和4种不同车轮材料的摩擦磨损行为.采用电子分析天平测量试样磨损量,采用SEM对试样进行微观分析.结果表明:随着车轮含碳量升高,车轮硬度升高,车轮的磨损量逐渐降低,而与之匹配的钢轨磨损量逐渐升高;轮轨试样的磨痕粗糙程度与磨损程度相关,磨损越严重,磨痕越粗糙;轮轨试样的硬度比决定轮轨试样的磨损机制,轮轨硬度比较低时,主要以磨粒磨损为主,磨损最严重,当轮轨硬度比继续升高,主要以疲劳磨损为主,磨损降低,当轮轨硬度比接近1.1时,轮轨氧化达到最严重,主要以氧化磨损为主.

In order to investigate the effect of wheel materials on the matching behaviors between wheel and rail,the MMS-2A wear test machine was used to simulate the friction and wear behavior of the wheel / rail systems made of U71 Mn hot-rolled rail and four kinds of wheel materials. The wear loss was measured by an electronic analytical balance and the microstructure of wheel / rail samples were analyzed by a scanning electron microscope. The results indicate that with the carbon content of wheels increasing,the wheel hardness increases and the wheel wear loss decreases,but the wear loss of the rail samples matching with the wheels increases gradually. The attrition rate of the wheel / rail samples is related to the roughness of the wear scars： the more serious the wear is,the rougher the wear scars are. In addition,the wear mechanism is determined by the hardness ratio of wheel to rail materials.When the hardness ratio is low,the wear process is dominated by a mechanism of abrasive wear,and the wear loss is the largest. With the increase of the hardness ratio,the main wear mechanism turns into a fatigue wear and the wear loss becomes less. When the hardness ratio approaches 1. 1,more serious oxidation occurs to the wheel / rail samples, and oxidative wear will dominate the wear mechanism.