原始组织对ER9车轮钢滚动接触疲劳性能的影响  

Influence of Original Microstructure on Rolling Contact Fatigue Properties of ER9 Wheel Steel

作　　者：刘旭东 刘鹏涛[1,2] 赵秀娟[1,2] 任瑞铭[1,2] LIU Xudong;LIU Pengtao;ZHAO Xiujuan;REN Ruiming(School of Material Science and Engineering,Dalian JiaoTong University,Liaoning Dalian 116028,China;Key Laboratory of Key Material of Rail Transit in Liaoning Province,Dalian JiaoTong University,Liaoning Dalian 116028,China)

机构地区：[1]大连交通大学材料科学与工程学院,辽宁大连116028 [2]大连交通大学辽宁省轨道交通关键材料重点实验室,辽宁大连116028

出　　处：《摩擦学学报》2021年第6期902-912,共11页Tribology

基　　金：国家重点基础研究发展规划项目(2015CB654802)资助。

摘　　要：利用双盘滚动接触疲劳试验机对原始组织分别为片状珠光体+先共析铁素体(P+PF)和回火索氏体(TS)的ER9车轮钢试样进行滚动接触疲劳试验,并对结果进行了分析。结果表明:在油润滑条件下,原始P+PF试样的滚动接触疲劳寿命是TS试样的2.8倍.其原因是原始的P+PF的试样表面存在厚约1μm的机加工细晶层,而TS试样无明显细晶层,在疲劳过程中,P+PF试样会优先在细晶层内萌生浅层裂纹并平行于表面扩展形成浅层剥落,而后在细晶层剥落的区域萌生疲劳裂纹,而TS试样则直接在试样表面萌生疲劳裂纹.经过1×10^(5)周次在空气中的预磨损后,两种不同原始组织的试样表面均被强化,滚动接触疲劳寿命均有大幅度的提升.但由于P+PF试样预磨损过程中机加工细晶层的剥落以及产生了少量的疲劳磨损,部分疲劳磨损裂纹成为滚动接触疲劳裂纹的裂纹源,而预磨损后的TS试样的表层形成分布更为均匀的细晶层,故预磨损后的TS试样的滚动接触疲劳寿命远高于P+PF试样.In recent years,with the continuous development of railway transportation,the speed of passenger trains has continued to increase.Rolling contact fatigue failure has become the main failure form of wheel-rail materials.In order to improve the rolling contact fatigue life of train wheels,the influence of original microstructure on rolling contact fatigue life of ER9 high speed wheel steel was analyzed.It provided theoretical and experimental basis for the design and damage control of key materials of rail transit.The ER9 wheel steel with the original microstructure of lamellar pearlite+proeutectoid ferrite(P+PF)was quenched and tempered to obtain the ER9 wheel steel with the original microstructure of tempered sorbite(TS).GPM-40 rolling contact fatigue testing machine was used for rolling contact fatigue test.Because the actual wheel-rail running process is the rolling contact fatigue phenomenon after a certain dry friction operation,in order to be closer to the engineering reality,the pre-wear of the ER9 wheel steels with two different original microstructures,and then the rolling contact fatigue test is performed.In this test,ER9 wheel steel is the main sample,and U71 Mn rail steel is used as the accompanying sample.Use FM-700 microhardness tester for hardness measurement,use USB digital microscope,Zeiss Supra 55 field emission scanning electron microscope with electron backscatter diffraction(EBSD)to observe and analyze the surface morphology,surface microstructure and crosssectional microstructure of two different original microstructure samples.Analyze the reasons for the difference in fatigue life of the two samples before and after pre-wear.Results:According to the principle of colloidal equilibrium,lamellar cementite is easier to dissolve.During machining,due to the interaction of cutting force and cutting heat,The original P+PF sample will form a machined fine-grain layer,which is unevenly distributed on the surface of the sample,the maximum thickness is about 1μm,while the original TS sample has no obvi

关 键 词：ER9车轮钢 片状珠光体 回火索氏体 裂纹 细晶层 预磨损 

分 类 号：TG142.21[一般工业技术—材料科学与工程]