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    打磨转速对重载铁路U75V钢轨材料去除行为的影响

    Effect of Grinding Rotation Speed on Material Removal Behaviors of U75V Steel Rail for Heavy Haul Railway

    • 摘要: 采用自主设计的钢轨打磨试验机对重载铁路U75V钢轨开展打磨试验,研究了不同打磨转速(1 000,2 000,3 000 r·min−1)下的材料去除行为与钢轨表面质量演变规律。结果表明:随着打磨转速的增加,钢轨的打磨量、摩擦因数均先降后升,钢轨/磨石界面的打磨温度升高,钢轨表面粗糙度增大,烧伤程度递增,磨痕数量减少,但其深度和宽度显著增大,磨痕均匀性明显下降,材料的塑性流动现象加剧;3 000 r·min−1打磨转速下钢轨表面产生横向裂纹;随着打磨转速的增加,因热-机耦合作用诱导产生的硬脆白层厚度显著增大,钢轨的材料去除机理从单一的磨削模式转变为磨削与剥落的复合模式。

       

      Abstract: Grinding tests of U75V steel rail used for heavy haul railway were conducted by a self-designed rail grinding testing machine, and the material removal behavior and the evolution law of rail surface quality under different grinding rotation speeds (1,000, 2,000, 3,000 r · min−1) were studied. The results show that as the grinding rotation speed increased, the grinding amount and friction coefficient of the steel rail first decreased and then increased, the grinding temperature at the interface between steel rail and millstone, the surface roughness and the degree of burning all increased, the number of grinding marks decreased and their depth and width increased significantly, the uniformity of grinding marks decreased significantly, and the plastic flow phenomenon of the material was intensified. There were transverse cracks on the surface of the rail at a grinding rotation speed of 3 000 r · min−1. With increasing grinding rotation speed, the thickness of the hard and brittle white etching layer induced by thermo-mechanical coupling effects increased significantly, and the material removal mechanism of the steel rail transformed from pure grinding mode to combined grinding-spalling mode.

       

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