激光冲击强化对回转支承用钢42CrMo表面性能的影响  

Effect of Laser Shock Peening on Surface Performance of Slewing Bearing Steel 42CrMo

作　　者：陈彬[1] 张兴权[1] CHEN Bin;ZHANG Xing-quan(Anhui University of Technology,Maanshan 243032,China)

机构地区：[1]安徽工业大学,安徽马鞍山243032

出　　处：《表面技术》2019年第2期62-68,共7页Surface Technology

基　　金：国家自然科学基金(51675002;51175002);安徽工业大学校青年教师科研基金(QZ201518)~~

摘　　要：目的研究激光冲击强化对回转支承用钢42CrMo表面形貌、表面硬度、微观组织和残余应力的影响,为后续研究激光冲击强化技术在回转支承上的应用提供指导和依据。方法采用高功率短脉冲的强激光束对回转支承用钢42CrMo试样进行激光冲击处理,然后用共聚焦显微镜进行表面形貌观察,用维氏硬度计测量冲击前后试样的表面硬度,用扫描电子显微镜观察截面微观组织结构,最后运用ABAQUS模拟激光冲击后的残余应力场。结果光斑直径为3 mm,脉冲宽度为8 ns,激光能量为2、3、4、5 J的情况下,激光冲击后产生的微凹坑最大深度分别为2.17、3.54、4.67、6.07μm,材料表面最高硬度较基体分别提高了10.10%、12.58%、13.58%、17.38%,材料表面的最大残余压应力分别为-210、-384、-495、-508 MPa。观察微观组织发现,激光冲击后塑性变形区的板条马氏体长度和宽度较基体材料更小,且分布更加均匀。结论激光冲击强化回转支承用钢42CrMo后,会在材料表面产生微米级的凹坑,并在材料表面和一定深度方向上产生残余压应力。在一定参数范围内,凹坑最大深度、材料表面硬度和最大残余压应力均随激光能量的增大而增大。回转支承用钢42CrMo的激光冲击强化机理是板条状回火马氏体的细化。The work aims to study effect of laser shock peening on the surface morphology, surface hardness, microstructureand residual stress of slewing bearing steel 42 CrMo and further provide guidance for the application of laser shock peeningtechnology in slewing bearing in the future. Laser shock treatment was applied to slewing bearing steel 42 CrMo sample withhigh-power short-pulse intense laser beam. Then, the surface morphology was observed by confocal microscope. The surfacehardness of the samples before and after shock was measured by vickers hardness tester. Cross section microstructure was ob-served by scanning electron microscope. Finally, the simulation software ABAQUS was used to simulate the residual stress fieldafter laser shock. In the case of spot diameter of 3 mm, the pulse width of 8 ns, and the laser energy of 2, 3, 4 and 5 J, the maxi-mum depth of micro-pit after laser shock was 2.17, 3.54, 4.67 and 6.07 μm, the maximum hardness of material surface was in-creased by 10.10%, 12.58%, 13.58% and 17.38% respectively and the maximum residual compressive stress of material surfacewas-210,-384,-495 and-508 MPa respectively. Microstructure observation results showed that the length and width of lathmartensite in plastic deformation layer after laser shock peening were smaller and more uniform than those in base material. Af-ter laser shock peening, micro-pit is produced on the surface of slewing bearing steel 42 CrMo, and the residual compressivestress is produced on the surface and in a certain depth direction of the material. Within a range of parameters, the maximumdepth, surface hardness and maximum residual compressive stress increase as the laser energy increases. The mechanism of la-ser shock peening to slewing bearing steel 42 CrMo is the refinement of lath tempered martensite.

关 键 词：激光冲击强化 42CrMo 表面形貌 表面硬度 微观组织 残余应力 

分 类 号：TG142.4[一般工业技术—材料科学与工程] TN249[金属学及工艺—金属材料]