不同制动初速度下铁路合成闸瓦磨屑的研究

Morphology and Composition of Debris of Organic Composite Railway Brake Shoe Under Different Braking Speed

磨屑可以提供摩擦磨损相关的信息,但目前有关铁路合成闸瓦磨屑组成的研究还不全面。在1∶1制动动力试验台上采用2种制动初速度进行了合成闸瓦制动试验,研究了2种制动初速度下合成闸瓦外观形貌、摩擦系数的变化,对比分析了磨屑的粒径、组成差异等。结果表明:与制动初速度35 km/h相比,125 km/h时合成闸瓦摩擦面形成了面积较大的第三体,导致摩擦系数减小;磨屑的粒径更细;磨屑中有机物含量减小,650℃下残重率从88.01%增加到93.08%;钙、硅、钡、硫、钾等无机元素含量增加;铁元素含量(质量分数)从59.61%减小到51.35%。分析认为,2种制动初速度下磨屑粒径和组成差异是由于较高制动初速度下产生的剪切力更大、摩擦表面温度更高导致的。

Wear debris can provide information about friction and wear.However,there is no report on the composition of wear debris of railway synthetic brake shoes.Therefore,a synthetic brake shoe was tested using a full-scale dynamometer brake test bench under two different initial braking speeds.Debris was collected.The wear debris was analyzed by laser particle size analyzer,thermogravimetric analyzer,X-ray fluorescence spectrometer and X-ray diffractometer.Compared with the initial braking speed of 35 km/h,the wear debris produced at the initial braking speed of 125 km/h was finer,at 650℃,the residual weight increased from 88.01%to 93.08%,the contents of inorganic elements such as Ca,Si,Ba,S and K increased.The content of iron decreased from 59.61%to 51.35%.The analysis showed that the difference of wear debris was due to higher shear force and higher friction surface temperature at the initial braking speed of 125 km/h.This study provides a reference for the study of friction and wear mechanism.