激光熔凝改性Q235钢表面的微观组织和力学性能演变分析  

Microstructure and mechanical properties evolution of Q235 steel surface modified by laser melting

作　　者：丁浩川 蓝永庭[1] 解远航 华振虎 张政 DING Haochuan;LAN Yongting;XIE Yuanhang;HUA Zhenhu;ZHANG Zheng(College of Mechanical and Automotive Engineering,Guangxi University of Science and Technology,Liuzhou 545006,Guangxi,China)

机构地区：[1]广西科技大学机械与汽车工程学院,广西柳州545006

出　　处：《钢铁研究学报》2024年第5期640-649,共10页Journal of Iron and Steel Research

基　　金：国家自然科学基金资助项目(12262003);广西自然科学基金资助项目(2022GXNSFAA035537);广西科技大学博士基金资助项目(校科博21Z13)。

摘　　要：为研究激光熔凝中激光功率和扫描速度对Q235材料表面的微观结构和宏观力学性能的影响规律,利用仿真软件模拟Q235受到激光照射时的熔池变化过程,并监测其中关键点的温度随时间变化趋势,利用金属材料相图分析计算软件分析Q235在升温和快速降温后所析出的金相组织。采用单因素激光熔凝实验法,对激光扫描后的材料利用金相显微镜观测其金相组织。结果发现,Q235母材的铁素体和珠光体,熔化后完全形成奥氏体,随后经过快速冷却形成贝氏体和马氏体,通过金相分析的结果验证了数值模拟结果的有效性。对微观组织与力学性能演变分析,表明在扫描速度一定的情况下,扫描功率的增加会使材料的强度得到提高,同时在功率为1250 W的激光照射下也使伸长率相对于1000W的激光功率下整体有所提高;经过激光处理表面后,整体拉伸强度提高的同时,伸长率下降。研究结果可为改善Q235钢的力学性能提供新工艺。To study the effect of laser power and scanning speed on the microstructure and macroscopic mechanical properties of Q235 material surface in laser melting,simulation software was used to simulate the change process of the molten pool when Q235 was irradiated by laser,and the temperature change trend of key points was monitored over time.Metallographic analysis software was used to analyze the microstructure of Q235 precipitated after temperature rise and rapid temperature drop.The metallographic microstructure of the material after laser scanning was observed by metallographic microscope using single factor laser melting experiment.The results show that the ferrite and pearlite of Q235 base metal form austenite completely after melting,and then form bainite and martensite after rapid cooling.The results of metallographic analysis verify the validity of the numerical simulation results.The analysis of microstructure and mechanical properties shows that the strength of the material is improved with the increase of scanning power at a certain scanning speed,and the elongation of the material is also improved with the laser power of 1250 W compared with the laser power of 1000 W;after laser treatment of the surface,the overall tensile strength increased,while the elongation decreased.The research results can provide a new process for improving the mechanical properties of Q235 steel.

关 键 词：Q235钢 激光熔凝 微观组织 力学性能 相图 

分 类 号：TG142.1[一般工业技术—材料科学与工程]