Jian Xiaoxia, Yang Xing, Li Jingqian, Wang Weihua, Wu Hebao
School of Mechanical and Electrical Engineering, Wuhan Institute of Technology, Guanggu 1st Road, Wuhan 430205, China.
School of Mechanical and Electrical Engineering Rongcheng Campus, Harbin University of Science and Technology, No. 52 Xuefu Road, Harbin 150080, China.
Materials (Basel). 2020 Dec 18;13(24):5799. doi: 10.3390/ma13245799.
Magnetic oscillation arc (MOA) technology was developed to avoid insufficient fusion defects appearing at the sidewalls in narrow gap gas tungsten arc welding (NG-GTAW). In this work, a unified model was developed to simulate the process of MOA assisted NG-GTAW. The model included the MOA, welding pool, workpiece and the coupling interaction between them. The heating characteristic of the MOA and the flow of liquid metal were simulated, and the mechanism of forming a uniform welding bead under MOA was investigated. It was found that if the magnetic flux density increased to 9 mT, the MOA could point to the sidewall directly; the maximum heat flux at the bottom declined by almost half and at the side, it increased by more than ten times. Additionally, the heat flux was no longer concentrated but dispersed along the narrow groove face. Under the effect of MOA, there were mainly two flow vortexes in the molten pool, which could further increase the heat distribution between the bottom, sidewall and corner, and was beneficial for the formation of a good-shape weld. The model was validated by experimental data.
磁振荡电弧（MOA）技术的开发是为了避免窄间隙钨极气体保护电弧焊（NG-GTAW）中侧壁出现熔合不足缺陷。在这项工作中，开发了一个统一模型来模拟MOA辅助NG-GTAW的过程。该模型包括MOA、熔池、工件以及它们之间的耦合相互作用。模拟了MOA的加热特性和液态金属的流动，并研究了在MOA作用下形成均匀焊缝的机理。研究发现，如果磁通密度增加到9 mT，MOA可以直接指向侧壁；底部的最大热流密度下降了近一半，而侧壁处则增加了十多倍。此外，热流不再集中，而是沿窄槽面分散。在MOA的作用下，熔池中主要有两个流动漩涡，这可以进一步增加底部、侧壁和拐角之间的热分布，有利于形成形状良好的焊缝。该模型通过实验数据进行了验证。
