摘要
针对某型动车组轴承外圈滚道面出现不同形式的剥离伤损,利用光学显微镜和扫描电子显微镜观察轴承外圈试样宏观伤损的形貌和剥离特征,分析轴承外圈内部的非金属夹杂物和氢致缺陷,研究轴承钢中非金属夹杂物、氢元素对滚动接触疲劳裂纹萌生和扩展的影响;使用有限元方法分析轴承外圈滚道面承载区的应力分布,进一步确定导致轴承外圈剥离伤损的破坏机理。研究表明:2个轴承外圈试样的滚道面剥离损伤均为典型的滚动接触疲劳伤损,剥离起源于外圈承载区上部的缺陷;其中一件轴承外圈滚道亚表面上存在大于临界尺寸的硬脆非金属夹杂物Al2O3,另一件轴承外圈中存在夹杂物和氢致缺陷,在滚动接触应力的作用下,这些缺陷导致和促进疲劳裂纹的萌生与扩展,使轴承外圈的滚道面上发生疲劳剥离损伤,损害了轴承的服役寿命。
Since there were many different types of raceway spallings on the outer rings of certain type of EMU bearings,the macroscopic failure morphology and spalling characteristics of the outer ring specimen were observed,and the non-metallic or hydrogen-induced defects in outer ring were analyzed by using optical microscope and scanning electron microscope.Furthermore,the influences of non-metallic or hydrogen in bearing steel on the crack initiation and propagation due to rolling contact fatigue were studied.The stress distribution on the load-supporting area of out ring raceway was analyzed by finite element method to further determine the failure mechanics led to the outer ring spallings.The results showed that the raceway spallings of two outer ring specimens belonged to typical rolling contact fatigue failure and the spallings initiated from the defects on the top of the load-supporting area of outer ring raceway.Therein,there were brittle non-metallic inclusions Al2O3 greater than critical size on the sub-surface of one outer ring raceway,and there were inclusions and hydrogen-induced defects in the other.Under the rolling contact stress,these defects caused and accelerated the initiation and propagation of fatigue cracks,which led to the fatigue spallings on outer ring raceway thus shortened the service life of railway bearing.
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2014年第3期78-82,共5页
China Railway Science
基金
国家"八六三"计划项目(2012AA03A503)
铁道部科技研究开发计划项目(2012J006-G)
关键词
轴承
滚道面剥离
机理
非金属夹杂物
氢致缺陷
滚动接触疲劳
动车组
Bearing
Raceway spalling
Mechanism
Non-metallic inclusion
Hydrogen-induced defect
Rolling contact fatigue
EMU
