不同介质对轮轨增黏与磨损特性影响

利用MMS-2A摩擦磨损试验机研究了水介质下砂、氧化铝、研磨子对轮轨增黏与磨损特性影响.结果表明:干态和水介质下随蠕滑率增大黏着系数呈先增加后小幅降低并趋于稳定.水介质下氧化铝介质的增黏效果最好,研磨子最差;砂介质使轮轨磨损严重且塑性流变层最厚,轮轨试样表面剥落严重;氧化铝介质下轮轨磨损量较砂介质小,塑性流变层轻微;研磨子介质下的轮轨试样磨损量最小,磨损表面较为光滑;落叶显著降低黏着系数,且易形成落叶浆,使接触表面产生划痕;落叶工况下撒砂能增加黏着系数且能去除落叶浆,但易造成轮轨试样的剥落损伤.

Effect of Medium on Improving Adhesion and Wear Characteristics of Wheel/rail

The effects of sand, alumina particles and abrasive agent on improving adhesion and wear behavior of wheel/rail under water conditions were investigated and explored using a MMS-2A testing apparatus. The results indicate that the adhesion coefficient of wheel/rail increased firstly and then gradually dropped to a stable value under the dry and water conditions. The effect of improving adhesion of spraying alumina particles was the best under the water condition and the effect of abrasive agent was relatively poor. The wear volume of wheel/rail specimens was maximal when sanding. The specimens exhibited serious surface spalling damage and there was obvious plastic deformation. The wear volume of wheel/rail specimens under the alumina particles condition decreased obviously compared with spraying sand. Furthermore, there was slight plastic deformation. The wear volume of wheel/rail specimens was the smallest and the wear surfaces of specimens were relatively smooth under the abrasive agent condition. Leaves markedly decreased adhesion coefficient of wheel/rail specimens. There was a thick layer of compressed leaves material on the contact interface of wheel/rail specimens. Sanding can increase adhesion coefficient and clear out the leaves layers. However, sanding aggravated spalling damage of wheel/rail specimens.