人工缺陷下感应淬火重载铁路车轴损伤容限评价  

Damage Tolerance Evaluation of Induction Hardening Heavy-duty Railway Axle under Artificial Defects

作　　者：吴鹏程 高杰维 赵海[4] 于文坛[4] 徐磊[5] 郭新凯 林鹏飞 陈宏[2] 韩靖[1] WU Pengcheng;GAO Jiewei;ZHAO Hai;YU Wentan;XU Lei;GUO Xinkai;LIN Pengfei;CHEN Hong;HAN Jing(School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China;School of Mechanical Engineering,Xihua University,Chengdu 610039,China;Guangdong Institute of Electronic and Information Engineering,UESTC,Guangdong Dongguan 523808,China;Maanshan Iron&Steel Co.,Ltd.,Hebei Maanshan 243000,China;School of Materials Science and Engineering,Xihua University,Chengdu 610039,China;Qingdao Sifang Co.,Ltd.,CRRC,Shandong Qingdao 266111,China)

机构地区：[1]西南交通大学材料科学与工程学院,成都610031 [2]西华大学机械工程学院,成都610039 [3]电子科技大学广东电子信息工程研究院,广东东莞523808 [4]马鞍山钢铁股份有限公司,河北马鞍山243000 [5]西华大学材料学院,成都610039 [6]中车青岛四方机车车辆股份有限公司,山东青岛266111

出　　处：《表面技术》2024年第19期173-185,共13页Surface Technology

基　　金：四川省重点研发计划(2023YFN0061,2023YFG0234);广东省基础与应用基础研究项目(2022A1515140111);山东省应用创新共同体项目(BZGDL-XM-2022-03)。

摘　　要：目的研究不同感应淬火工艺对重载铁路车轴钢试样梯度结构的影响,阐明不同人工缺陷下感应淬火试样的疲劳断裂行为,并评价损伤容限,为重载铁路车轴感应淬火工艺设计和损伤容限评价提供理论基础和评价方法。方法在AAR-CM车轴钢试样表面采用不同感应淬火工艺参数制备不同深度淬硬层,采用X射线测量淬硬层残余应力分布,通过电火花和空气炮在正火态和感应淬火试样表面制备不同尺寸的电火花或冲击损伤,采用疲劳试验机研究损伤试样的弯曲疲劳性能,借助光学显微镜和扫描电镜分析试样的损伤机理和疲劳断裂行为,并对其疲劳性能进行评价。结果在3种工艺下感应淬火试样有效淬硬层深度分别为800、1200、1400μm。在电火花缺口尺寸较小时,感应淬火试样的疲劳强度比正火态试样高出50%。在冲击损伤尺寸较小时,感应淬火试样的疲劳强度比正火态试样高出40%。较小的尺寸冲击损伤对正火态和感应淬火处理试样的疲劳强度无影响。结论感应淬火可提高重载铁路车轴钢试样表面强度,进而提高其耐冲击性能,残余压应力减弱了电火花缺口试样和低速冲击损伤对试样疲劳强度的影响,高速冲击破坏了试样表面完整性,并削弱了残余压应力的作用,试样的疲劳强度急剧降低。文中设计的淬硬层深度对感应淬火试样损伤容限的影响较小。To provide a theoretical basis and evaluation method for surface induction hardening process designing and damage tolerance evaluation of heavy-duty railway axles,the paper studied the evolution of microstructure,hardness,and residual stress gradient of the hardened layer of heavy-duty railway axle steel specimens under different induction hardening processes,analyzed the damage mechanism of defects introduced by EDM(electrical discharge machining)notch and impact damage,clarified the fatigue fracture behavior of induction hardening specimen under different artificial defects and evaluated its damage tolerance.The AAR-CM heavy-duty railway axle steel was used to prepare testing specimens.The hardened layers with different depths were prepared on the surface of the specimens by different induction hardening process parameters,and the residual stress distribution of the hardened layer was measured by X-ray.Different sizes of EDM notch or impact damage were prepared on the surface of untreated(normalized)and induction hardening specimens by EDM and air gun.The bending fatigue properties of the specimens under different damage were studied with a fatigue testing machine.The damage mechanism and fatigue fracture behavior of the specimens were analyzed with an optical microscope and a scanning electron microscope.Through metallographic observation,hardness test,damage morphology characterization,and fatigue fracture analysis,the fatigue properties of normalized and induction hardening specimens under different damage degrees were evaluated respectively.The results showed that the surface structure of the specimen changed from pearlite and ferrite to martensite during the induction hardening process.The effective hardened layer depths of the induction hardening specimens under the three processes were 800μm(M1),1200μm(M2),and 1400μm(M3),respectively.The thicker the effective hardened layer,the greater the surface hardness and residual stress.The shape of the EDM notch was regular.The impact damage shape of the normal

关 键 词：铁路车轴 感应淬火 淬硬层深度 人工缺陷 损伤容限 

分 类 号：TB31[一般工业技术—材料科学与工程]