连续高功率激光辐照对55号钢组织和硬度的影响  

Effect of Continuous High-Power Laser Irradiation on Microstructure and Hardness of 55 Steel

作　　者：杨仁人 林英华[1,2] 彭龙生 黄伟 王新林 Yang Renren;Lin Yinghua;Peng Longsheng;Huang Wei;Wang Xinlin(College of Mechanical Engineering,University of South China,Hengyang 421001,Hunan,China;Hunan Key Laboratory of Ultra-Fast Micro Technology and Advanced Laser Manufacturing,Hengyang 421001,Hunan,China;Hunan Lifang Roller Co.,Ltd.,Hengyang 421681,Hunan,China;Hunan High Wear Resistant Alloy Material Advanced Manufacturing Engineering Technology Research Center,Hengyang 421681,Hunan,China)

机构地区：[1]南华大学机械工程学院,湖南衡阳421001 [2]超快微纳米技术与激光先进制造湖南省重点实验室,湖南衡阳421001 [3]湖南力方轧辊有限公司,湖南衡阳421681 [4]湖南省高耐磨合金材料先进制造工程技术研究中心,湖南衡阳421681

出　　处：《中国激光》2023年第16期155-166,共12页Chinese Journal of Lasers

基　　金：湖南省自然科学基金-省市联合基金(2022JJ50019);衡阳市指导性计划项目(hyzdxjh202101);南华大学人才引进项目(210XQD017);南华大学研究生科研创新项目(223YXC007)。

摘　　要：为了改善55号钢在传统淬火过程中的不足,笔者采用连续高功率光纤激光器作为热源进行辐照,以期使55号钢表面获得更好的组织和更高的表面硬度。利用单一变量原则获得了不同功率下的激光重熔与激光淬火工艺参数,研究了两者对55号钢微观组织和硬度的影响。结果表明:激光重熔比激光淬火具有更好的硬化效果。在保证试样表面平整的前提下,淬火试样获得的表面硬度和硬化层深度分别为446~520 HV、621~709μm,而重熔试样获得的表面硬度和硬化层深度分别为480~613 HV、709~813μm。通过分析硬化层的微观组织、物相、元素组成,发现这主要归因于重熔试样的硬化层中具有比淬火试样更多的马氏体、更均匀致密的微观组织以及更少的未熔碳化物。本研究结果为55号钢表面激光硬化提供了参考。Objective We uses the high-energy heat source of a high-power laser(20 kW)to address the problems of surface oxidation,decarburization behavior,uneven surface hardness,high costs,and environmental pollution in the conventional quenching process of 55 steel surface.By promoting the application of high-power lasers and technological innovation,the study aims to meet practical working conditions for high efficiency,low cost,energy conservation,and environmental protection.The single-variable principle is employed to obtain laser remelting and laser quenching process parameters with different laser power ranges,and the effects of both on the surface morphology,microstructure,and hardness of 55 steel are investigated.The goal is to enhance the working surface properties of 55 steel,thereby increasing its service life and safety,and reducing the likelihood of engineering accidents.Methods In the study of laser quenching on the surface of 55 steel,we found that neither an excessively high laser power nor an excessively quick scanning speed could improve the surface properties of the steel,particularly under high-power laser quenching with fast scanning.The hardened surface expanded with increased laser power,and despite remelting,the hardness value remained relatively constant.Consequently,a comparative study of laser remelting and laser quenching was proposed.First,to investigate the hardening effect of laser remelting and laser quenching on the working surface of 55 steel,the variation of surface hardness in specimens with increasing laser power at different laser ranges was investigated using the single variable principle,and the surface morphology and boundary thermal diffusion of each specimen were analyzed.Second,the effect of scanning speed on the surface hardness of 55 steel was investigated at medium laser power ranges to further characterize the hardening differences between laser remelting and laser quenching on that material.To characterize the intrinsic hardening difference between these processes,XRD analy

关 键 词：激光技术 激光淬火 激光重熔 55号钢 硬度 微观组织 

分 类 号：TG162.7[金属学及工艺—热处理]