CRH380A型高速动车组制动闸片摩擦损伤分析

Wear Analysis of Brake Pad for CRH380A High-speed Train

本研究中选取CRH380A型高速动车组服役中的制动闸片作为研究对象,利用微观分析测试手段分析了该闸片摩擦粒子的损伤特征及其原因,得出摩擦粒子的主要损伤特征为剥落和裂纹.根据闸片摩擦粒子形貌和成分分析结果,结合不同制动时刻摩擦粒子的应力分布状态,分析了形成以上两种主要损伤的原因和机理.结果表明:闸片摩擦粒子材料加工过程中形成的气穴、不同组元的硬度和耐磨性差异等应是导致其发生块状剥落的主要原因;而制动闸片切入端的摩擦粒子应力较大,这可能是导致制动闸片偏磨的主要原因之一,且摩擦粒子的中心圆孔附近存在应力集中现象,导致了裂纹更容易在圆孔周边萌生,同时材料加工过程中形成的气穴、不同组元之间结合强度不足等原因也导致了裂纹的萌生与扩展.

In this study,a serviced brake pad on CRH380A high-speed train was collected,and the wear features and corresponding wear mechanisms of the brake pad were analyzed by different micro-analysis methods.Exfoliation and cracks were found to be the main wear features of the brake pad.Combining the microscopic analysis of the worn surface and the finite element analysis of stress distribution at different friction blocks,the wear mechanisms of the two kinds of wear features above were clarified.The results show that the exfoliation of the friction block was mainly caused by the micropores formed during material processing,and the difference of the material components'hardness and wear resistance.The contact stress concentrated on the leading edge of brake pad may be one of the leading reasons for the nonuniform wear.In addition,stress concentration can be found near the center hole of the friction block,which made the initiation of cracks much easy around the edge of the hole.The micropores formed during their material processing and the insufficient bonding strength between different components also led to the initiation and propagation of cracks.