Al-Si镀层22MnB5激光焊的熔池流动特性及元素分布  

Flow characteristics and element distribution of melten pool in 22MnB5 laser welding with Al-Si coating

作　　者：朱李斌 汪乾 潘宣军[1] 李思良 葛星 张衡 刘海江[1] ZHU Libin;WANG Qian;PAN Xuanjun;LI Siliang;GE Xing;ZHANG Heng;LIU Haijiang(School of Mechanical Engineering,Tongji University,Shanghai,200092)

机构地区：[1]同济大学,机械与能源工程学院,上海200092

出　　处：《焊接学报》2024年第6期1-11,共11页Transactions of The China Welding Institution

摘　　要：熔池流动行为对镀层元素在焊缝中的分布起决定性作用.采用建立激光焊熔池三维瞬态数值模型的方法,分析AlSi镀层22MnB5高强度钢激光焊的熔池流动行为及其对焊缝中Al元素分布的影响规律.在焊接试验中,根据能谱仪对焊接接头的扫描数据验证数值模型的可靠性.结合模拟结果与试验结果对激光焊熔池流动行为及焊缝Al元素分布规律进行研究.结果表明,根据激光焊热输入与功率密度阈值的不同,熔池形貌呈现无匙孔、未完全贯穿匙孔和完全贯穿匙孔3种特征,并存有不同的温度场、流场、流速和稳定性.无匙孔熔池由于流速分布均匀,涡流产生较少,稳定性最好.镀层Al元素在焊接接头上下焊趾区域易产生偏聚,较之上表面镀层,下表面镀层进入熔池后Al元素偏聚现象更明显.因此,上部Al元素均质化分布显著优于下部.The flow behavior of the molten pool plays a decisive role in the distribution of coating elements in the weld seam.By establishing a three-dimensional transient numerical model of the laser welding molten pool,the flow behavior of the molten pool in laser welded of 22MnB5 high-strength steel with Al-Si coating and its influence on the distribution of Al elements in the weld seam were analyzed.In the welding experiment,The reliability of the numerical model was verified based on the scanning data of the welding joint using an energy spectrometer.The flow behavior of the laser welding melten pool and the distribution of Al element in the weld seam were studied by combining simulation and experimental results.The results showed that,according to the different energy and power density thresholds of the laser welding line,the morphology of the melten pool presented three characteristics:keyhole free,partially penetrated keyhole,and fully penetrated keyhole,with significant differences in temperature field,flow field,flow rate and stability.The keyless molten pool has the best stability due to its uniform flow velocity distribution and less vortex generation;The Al element in the coating is prone to segregation in the upper and lower weld toe areas of the welded joint.Compared to the upper surface coating,the Al element segregation phenomenon is more obvious when the lower surface coating enters the molten pool.Therefore,the homogenization distribution of the Al element in the upper part is significantly better than that in the lower part.

关 键 词：Al-Si镀层22MnB5高强度钢 数值模拟 熔池流动 Al元素均质化 

分 类 号：TG456.7[金属学及工艺—焊接] T665[一般工业技术]