CO_2短路过渡焊接熔池三维瞬态数值模拟  

Three-dimensional transient numerical simulation of melting pool in CO_2 short-circuiting arc welding

作　　者：夏胜全[1] 孙晓明[2] 

机构地区：[1]中国工程物理研究院,绵阳621900 [2]清华大学先进成形制造教育部重点实验室,北京100084

出　　处：《焊接学报》2016年第1期115-119,134,共5页Transactions of The China Welding Institution

摘　　要：考虑CO_2短路过渡焊接过程中的随机性,建立了考虑熔滴熔池短路时刻、熔滴初始大小等因素的熔滴自适应模型.此外,采用非对称高斯热源模型来考虑电弧热流密度沿焊接方向的非对称性,结合附加源项法考虑电弧压力、电磁力和浮力,采用连续表面张力模型计算表面张力,采用VOF方法追踪熔池表面,采用焓-孔隙度法考虑熔化凝固过程中的糊状区的动量损失,建立了CO_2短路过渡焊接熔池的三维瞬态模型.利用该数学模型计算6 mm厚低碳钢板的CO_2短路过渡焊接熔池的温度场和流场的瞬态发展,模拟和试验结果的短路间隔时间概率密度分布及焊缝成形吻合良好.Due to the randomness in the CO_2 short-circuiting arc welding,the adaptive model of droplet considering the initial size,the initial temperature and the time of short-circuits between drop and melting pool is set up in the numerical model.Then the three-dimensional transient model of CO_ 2 short-circuiting transfer welding pool was set up. In model,the asymmetric Gauss heat source was adopted taken into account the asymmetric of welding arc's heat flux density along welding direction,the VOF model was adopted to track the gas-liquid interface,the enthalpy-porosity technique was used to compute the momentum sink in the mush zone; the additional source term method was used to add the main force of pool,such as arc pressure,the electromagnetic force,the buoyancy and so on. The evolution of the temperature field and flow field was computed with the model in the CO_2 short-circuiting arc welding of 6mm thick low carbon steel. The probability density distribution of short-circuiting time interval and the final weld formation under the simulation condition was well agreed with experimental result.

关 键 词：短路过渡 熔池 熔滴自适应模型 

分 类 号：TG444[金属学及工艺—焊接]