西南交通大学学报2024，Vol.59Issue(6)：1305-1313,9.DOI:10.3969/j.issn.0258-2724.20220257
超声滚压EA4T车轴钢疲劳性能及寿命预测
Fatigue Properties and Life Prediction of Ultrasonic Rolling EA4T Axle Steel
摘要
Abstract
In order to study the influence of surface ultrasonic rolling processing(SURP)on the fatigue properties of EA4T axle steel,the EA4T axle steel specimens were firstly treated by SURP technology,and the surface properties of the treated specimens were analyzed.The 3D surface morphologies,roughness,hardness,residual stress,full width at half maximum(FWHM),and crystal size were investigated.Then,the fatigue tests were carried out on the EA4T axle steel specimens using a rotary bending fatigue testing machine.The stress-fatigue life(S-N)curves and crack propagation behaviors were obtained,and the effect of SURP on fatigue properties and crack propagation behaviors of EA4T axle steels was analyzed.Finally,a back propagation(BP)neural network was used to establish the fatigue life prediction model of SURP EA4T axle steel,which took load stress amplitude,surface roughness,surface FWHM,surface hardness,hardened layer depth,surface residual stress,and depth of residual stress layer as input.In addition,the life of SURP EA4T axle steel specimens was predicted.The results show that SURP can reduce the surface roughness of the specimens to 0.17 μm and remove the groove morphology.Meanwhile,the surface hardness of the specimens is improved to 420 HV,and a surface residual stress of about-500 MPa and a residual stress layer with a depth of about 550 μm are introduced.There are conventional fatigue limits for grinding specimens,grinding with polishing specimens,as well as SURP specimens.The fatigue properties of grinding specimens and grinding with polishing specimens are basically the same,with a fatigue limit of 355 MPa.The fatigue property of SURP specimens is improved significantly,with a fatigue limit of 455 MPa,an increase of 28%compared with the grinding specimens.Fatigue fracture observations show that the fatigue cracks of all specimens initiate from the surface,and SURP cannot change the fatigue damage mechanism of the specimen.SURP can increase the threshold value of crack propagation of the specimen from 6.29 MPa·m1/2 to 11.21 MPa·m1/2,and it can slow down the crack initiation and propagation of short cracks,thus significantly improving the fatigue property of EA4T axle steel.The fatigue life prediction model of SURP EA4T axle steel has a prediction accuracy of 88.5%.关键词
EA4T车轴钢/超声滚压/疲劳性能/裂纹扩展门槛值/BP神经网络Key words
EA4T axle steel/ultrasonic rolling/fatigue property/threshold value of crack propagation/BP neural network分类
交通运输引用本文复制引用
张继旺,张浩楠,杨冰,苏凯新,李行..超声滚压EA4T车轴钢疲劳性能及寿命预测[J].西南交通大学学报,2024,59(6):1305-1313,9.基金项目
国家自然科学基金项目(51675445) 牵引动力国家重点实验室自主研究课题(2019TPL-T06). （51675445）
