• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2019, Vol. 55 ›› Issue (18): 63-69.doi: 10.3901/JME.2019.18.063

• 材料科学与工程 • 上一篇    

摇动电弧窄间隙FCAW立焊流体流动数值分析模型

胥国祥, 朱杰, 王加友, 李林, 郑志强   

  1. 江苏科技大学江苏省先进焊接技术重点实验室 镇江 212003
  • 收稿日期:2019-01-31 修回日期:2019-06-05 发布日期:2020-01-07
  • 通讯作者: 王加友(通信作者),男,1964年出生,教授,博士研究生导师。主要研究方向为摇动电弧窄间隙焊工艺及机理。E-mail:zj_jiayouw@126.com
  • 作者简介:胥国祥,男,1981年出生,博士,副教授,硕士研究生导师。主要研究方向为激光焊、摇动电弧窄间隙焊及焊接过程数值模拟。E-mail:xugxiang@163.com
  • 基金资助:
    国家自然科学基金(51475218)和江苏省“青蓝工程”资助项目。

Numerical Analysis Model for Fluid Flow in Swing Arc Narrow Gap Vertical FCAW

XU Guoxiang, ZHU Jie, WANG Jiayou, LI Lin, ZHENG Zhiqiang   

  1. Key Laboratory of Advanced Welding Technology of Jiangsu Province, Jiangsu University of Science and Technology, Zhenjiang 212003
  • Received:2019-01-31 Revised:2019-06-05 Published:2020-01-07

摘要: 目前关于摇动电弧窄间隙药芯焊丝气体保护焊(Fluxed-cored arc welding,FCAW)的研究较少涉及熔池内部物理现象,缺乏对其成形机理的深入认识,从而影响了焊接质量的稳定性,因此利用数值模拟方法对熔池动态行为进行研究,利于焊接参数的优化及质量可靠性的提高。基于FLUENT软件,建立了适用的摇动电弧窄间FCAW立焊熔池流体流动数值分析模型,将电弧热输入视为双椭圆平面热源,并同时考虑了电弧移动路径、移动方向和接头几何特征对电弧热流分布的影响,将金属和熔渣填充过程视为液体金属和熔渣从熔池上部流入过程;假定两者流速相同,并通过对流速施加时间脉冲函数表征过渡频率。此外,模型还考虑了导电杆折弯角度对电弧力的影响。利用FLUENT软件对药芯焊丝摇动电弧窄间隙立焊熔池动态行为进行模拟计算。结果表明,模型能够合理地描述药芯焊丝窄间隙立焊熔池液体金属和熔渣的流体动力学特征,计算结果和试验结果吻合较好。熔池纵截面中部区域出现涡流,熔渣向坡口中间部位聚集;向上的电弧应力分量和熔渣有助于抑制熔池下淌。

关键词: 药芯焊丝, 窄间隙焊, 流体流动, 立焊, 数值模拟

Abstract: There are few studies involving the interior physical phenomenon in swing arc narrow gap fluxed-cored arc welding (FCAW) currently, which leads to a lack of deep understanding of weld formation mechanism, thus affecting the stability of welding quality. Based on FLUENT software, an adaptive numerical analysis model for swing arc narrow gap FCAW in vertical position is developed. Arc heat input is modeled as a double elliptic plane heat source, which considered the effects of swing arc, arc moving direction and geometrical feature of welded joint. The filling of metal and slag is regarded as the process of liquid metal and melting slag flowing into the weld pool and it is assumed that they have the same flowing velocity. The time pulse function is applied to the flowing velocity of melting metal and slag to consider the transfer frequency. Besides, the influence of bent angle of conductive rod is also taken into account. Using FLUENT software, weld pool dynamic behavior in swing arc narrow gap vertical FACW is simulated. The results show that the built model can describe the dynamic feature of melting metal and slag in swing arc narrow gas vertical FCAW and the calculated results agree well with experimental data. A vortex occurs in the middle part of weld pool longitudinal section and the slag tends to accumulate at the middle part of the groove. The upward component of arc force and slag can improve the fluid flow pattern and help to suppress the sagging of liquid metal in vertical welding.

Key words: flux-cored wire, narrow gap welding, fluid flow, vertical welding, numerical simulation

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