摘要
为了研究激光冲击强化对LZ50车轴钢疲劳性能的影响,对LZ50车轴钢车轴试样进行激光冲击强化处理并在JD-1轮轨模拟试验机上进行了旋转弯曲疲劳试验。结果显示:采用不同参数激光冲击强化处理的2个试样,硬度分别增大18%和27%;对LZ50车轴钢试样的过盈配合面进行激光冲击处理后产生了塑性变形层,形成了较高的残余压应力;试验后试样过盈配合表面两侧区域都可见明显的环形损伤带,出现了以剥落和犁沟为特征的磨损形貌,损伤机制为磨粒磨损、氧化磨损和剥层。激光冲击前后试样断口形貌特征相似,疲劳源呈多源性;在裂纹扩展区域段观察到大量的准解理小面,属于脆性穿晶断裂;瞬断区内出现大量韧窝和二次裂纹。激光冲击强化处理显著提高了车轴钢的疲劳寿命,不同激光冲击强化参数处理的2个车轴试样疲劳寿命比未处理试样疲劳寿命分别提高31%和21%。
The present work aimed to improve fatigue performance of LZ50 axle steels by using LSP methods.LSP was applied to the surface of LZ50 axle steel specimens,the JD-1 wheel/rail simulation machine was used to explore the fatigue performance of LZ50 axle steels under LSP with different parameters.The surface hardness of two axle specimens with different parameters of LSP significantly increases at the rate about 18% and 27%,respectively.After LSP at the interference fitted surface of the LZ50 axle steel specimens,a plastic deformation layer was generated,resulting in a high residual compressive stress.After test,both sides of the interference fitted surfaces emerged annular band damages which presented plough and spalling,and the damage mechanism was abrasive wear,oxidation wear and delamination.The morphology feature of fracture surface before and after LSP is similar and fatigue crack initiation is multisource.Many of quasi-cleavage fracture in the propagation area are trans-granular fracture mode.A large number of dimples and second cracks appeares in the final fracture area.The fatigue life of the axle materials is obviously improved by LSP,and the fatigue life rate of the two treated axle specimens with different parameters increases by 31% and 21%,respectively.
作者
唐凯
周留成
何卫峰
王文健
郭俊
刘启跃
TANG Kai;ZHOU Liucheng;HE Weifeng;WANG Wenjian;GUO Jun;LIU Qiyue(State Key Laboratory of Traction Power,Southwest Jiaotong University,Chengdu,610031;Engineering Institute,Air Force Engineering University,Xi’an,710038)
出处
《中国机械工程》
EI
CAS
CSCD
北大核心
2020年第3期267-273,共7页
China Mechanical Engineering
基金
国家重点研发计划资助项目(2016YFB1102601)
牵引动力国家重点实验室自主研究课题资助项目(2018TPL-T02)
关键词
激光冲击强化
LZ50车轴钢
疲劳性能
残余应力
塑性变形
laser shock processing(LSP)
LZ50 axle steel
fatigue performance
residual stress
plastic deformation
