CL70车轮钢原始组织对接触疲劳性能的影响  

Effect of Original Microstructure on Contact Fatigue Property of CL70 Wheel Steel

作　　者：冯小豪 潘金芝[1,2] 刘鹏涛[1,2] 赵秀娟[1,2] FENG Xiaohao;PAN Jinzhi;LIU Pengtao;ZHAO Xiujuan(School of Material Science and Engineering,Dalian 116028,Dalian JiaoTong University,China;Key Laboratory of Key Material of Rail Transit in Liaoning Province,Dalian JiaoTong University,Dalian116028,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：《热加工工艺》2023年第22期67-71,77,共6页Hot Working Technology

基　　金：国家重点基础研究发展规划项目(973)(2015CB654802)。

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+F)和回火索氏体(TS)的CL70车轮钢试样进行磨损和滚动接触疲劳试验。利用光学显微镜、扫描电镜和硬度计对组织和硬度进行分析,分析原始组织对疲劳性能的影响。结果表明:P+F试样与TS试样经过预磨损后表面出现不同的磨损机制,P+F试样表面主要为疲劳磨损,并伴随起皮现象。TS试样表面主要为黏着磨损和磨粒磨损,有轻微的疲劳磨损;两种原始组织表层都为细小的铁素体基体上分布着细小的渗碳体,但P+F试样表层晶粒更细小,硬度更高,变形层厚度也小。对预磨损后的两种试样进行了接触疲劳试验结果得出,TS试样的疲劳寿命是P+F试样的4.4倍。疲劳试样的表面形貌是:TS试样在疲劳后主要是表面局部出现典型的疲劳剥落深坑,而P+F试样主要是表面为麻点状剥落伴随着剥落深坑。预磨损在细化组织和提高硬度的同时减小疲劳磨损,将有利于疲劳寿命的提高。The wear test and rolling contact fatigue test of CL70 wheel steel specimens with the original structure of lamellar pearlite+proeutectoid ferrite(P+F)and tempered sorbite(TS)were carried out using double-disk rolling contact fatigue tester.The optical microscope,scanning electron microscope and hardness tester was used to analyze the structure and hardness.The influences of original structure on the fatigue performance were studied.The results show that:P+F specimen and TS specimen have different wear mechanisms on the surface after pre-wearing.The surface of P+F specimen is mainly fatigue wear,and accompanied by peeling phenomenon.The surface of the TS specimen is mainly adhesive wear and abrasive wear,with slight fatigue wear;the surface layers of the two original structures are fine ferrite matrixes with fine cementite,but the surface grains of the P+F specimen are smaller,the hardness is higher,and the thickness of the deformation layer is also thin.The contact fatigue test results of the two pre-wear specimens show that the fatigue life of the TS specimen is 4.4 times higher than that of the P+F specimen.The surface morphology of the fatigue specimens are that after fatigue,the TS specimen mainly has typical fatigue spalling deep pits on the surface,while the P+F specimen mainly has pitting flaking on the surface accompanied by spalling deep pits.Pre-wear can refine the structure and increase the hardness,while reduce the fatigue wear,which help improve the fatigue life.

关 键 词：CL70车轮钢 片状珠光体 回火索氏体 预磨损 疲劳裂纹 组织演变 

分 类 号：TG142.11[一般工业技术—材料科学与工程]