• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2018, Vol. 54 ›› Issue (12): 193-206.doi: 10.3901/JME.2018.12.193

• 材料科学与工程 • 上一篇    下一篇

外加横向磁场作用电弧增材成形过程中的传热传质仿真

周祥曼1,2, 田启华1,2, 杜义贤1,2, 柏兴旺3, 张海鸥4   

  1. 1. 三峡大学机械与动力学院 宜昌 443002;
    2. 水电机械设备设计与维护湖北省重点实验室(三峡大学) 宜昌 443002;
    3. 南华大学机械工程学院 衡阳 421001;
    4. 华中科技大学机械科学与工程学院 武汉 430074
  • 收稿日期:2017-09-25 修回日期:2018-03-09 出版日期:2018-06-20 发布日期:2018-06-20
  • 通讯作者: 田启华(通信作者),男,1962年出生,博士,教授。主要从事机械设计及理论、CAD/CAE/CAM技术、制造业信息化方面的研究。E-mail:tqh@ctgu.edu.cn
  • 作者简介:周祥曼,男,1983年出生,博士,讲师。主要从事电弧增材制造工艺与多尺度数值模拟的研究。E-mail:zhouxman@ctgu.edu.cn
  • 基金资助:
    国家自然科学基金(51705287,51475265,51775308)和水电机械设备设计与维护湖北省重点实验室(三峡大学)开放基金(2017KJX05)资助项目。

Simulation of Heat and Mass Transfer in Arc Welding based Additive Forming Process with External Transverse Magnetic Field

ZHOU Xiangman1,2, TIAN Qihua1,2, DU Yixian1,2, BAI Xingwang3, ZHANG Haiou4   

  1. 1. College of Mechanical and Power Engineering, China Three Gorges University, Yichang 443002;
    2. Hubei Key Laboratory of Hydroelectric Machinery Design & Maintenance, China Three Gorges University, Yichang 443002;
    3. School of Mechanical Engineering, University of South China, Hengyang 421001;
    4. School of Mechanical Science & Enginnering, Huazhong University of Science and Technology, Wuhan 430074
  • Received:2017-09-25 Revised:2018-03-09 Online:2018-06-20 Published:2018-06-20

摘要: 为了揭示外加横向磁场对电弧增材成形过程中电弧和熔池传热传质以及成形件微观组织影响的内在机理,建立基于GMAW电弧增材成形过程中电弧和熔池的弱耦合数值模型,通过数值模拟对比分析了有/无外加横向磁场作用下熔池电磁力分布、电弧和熔池传热传质的差异,发现横向磁场作用使电弧向熔池后方偏转,使熔池发生单向强制对流并驱动熔融金属和热量向熔池后方运动,从而更加直接地冲刷熔池结晶面。由此预测横向磁场作用能降低熔池凝固过程中枝晶前沿温度梯度和溶质浓度,提高枝晶前沿的成分过冷,使得靠近熔池中心的枝晶前端生长加速并细化晶粒。相同工艺条件的对比试验表明:相比无外加磁场的普通熔积,横向磁场作用下熔池底部等轴晶区域减小,整个结晶面上细密的胞状枝晶区域面积增大,验证了数值模拟的预测。研究结果可为外加磁场在电弧增材成形微观组织控制中的应用提供依据和参考。

关键词: 传热传质, 电弧增材成形, 横向磁场

Abstract: In order to reveal the inherent mechanism of the influence of transverse magnetic field on heat and mass transfer of the arc and molten pool in arc welding based additive forming(AWAF) process, and the microstructure of the AWAF parts, a three-dimensional weak coupling numerical model of arc and metal transport is developed to simulate the arc, molten pool dynamic in GMAW baesd AWAF process. The studies of with and without external transverse magnetic field treatment in AWAF process are applied to analyze the electromagnetic force distribution in molten pool, the differences of heat and mass transfer of arc and molten pool by numerical simulation. The analytical results show that the external transverse magnetic field can deflect the arc toward the rear of molten pool, induce forced convection in one direction, drive the molten metal and heat to the rear of molten pool, and wash against the dendrite frontier more directly in molten pool. Therefore, it can predict that external transverse magnetic field enables the capacity of decreasing the temperature gradient and solute concentration at the front of dendritic during the solidification of the molten pool, which is able to increase the concentration undercooling of this area, increase the growth rate of dendritic that near the center of the molten pool and refine grains. The comparative experiments show that the external transverse magnetic field treatment can reduce the area of equiaxed zone at the bottom of molten pool as well as increase the area of refined cellular dendrite zone. The experimental results verify the predictions of numerical simulation. The conclusions of the above study provide the basis and reference for the application of the external magnetic field in the control of microstructure of AWAF parts.

Key words: arc welding based additive forming, heat and mass transfer, transverse magnetic field

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