风沙冲蚀对钢轨焊缝区的影响

Effect of Sand Erosion on Rail Weld Zone

针对新疆特大风区铁路钢轨遭受风沙冲蚀现状,研究风沙对钢轨焊缝区的冲蚀行为。采用气流挟沙法模拟风沙环境,分别对焊缝区及母材试样进行冲蚀试验;试验方案依据正交试验原理设计,用失重测量法测量试样冲蚀率,研究冲蚀率与沙粒直径、冲蚀速度和冲蚀角度的关系;用扫描电镜(SEM)观察试样冲蚀表面微观形貌,分析冲蚀机理。结果表明,冲蚀速度是影响焊缝和母材冲蚀率的主要因素,速度越大,冲蚀率越大;冲蚀角度对焊缝和母材的影响,随角度的增大而减少;相同情况下,母材的冲蚀率大于焊缝区的冲蚀率;在材料弹性模量一致的情况下,材料的硬度在抗冲蚀能力方面起到重要作用。

Aiming at the wind erosion situation of railway line in gale areas in Xinjiang, the erosion behavior of rail was studied under windy and dusty circumstance. Using sediment-laden air flow method, the sand environment was simulated. The erosion tests were conducted respectively both on the weld zone and matrix metal specimen. The test program was designed based on the principle of orthogonal experimental to improve the efficiency. The weightlessness measurement was employed to evaluate the erosion rate of the sample. The relationship between the erosion rate of the samples and diameter of the sand,the velocity, and the impact angle was studied. Using SEM, the specimen morphology was observed, the erosion mechanism was analyzed. The results show that： the erosion velocity is the main factor for affecting the erosion rate of weld and matrix metal, and the higher the velocity, the higher the erosion rate. While the erosion rates decrease with impact angle increasing.Under the same circumstances, the erosion rate of the matrix metal is greater than that of the weld zone. The hardness plays an important role in material erosion wear resistance at the same elastic modulus.