Discussion on the tendency of porosity in weld of CO₂ arc welding based on the theory of bubble escape velocity

基于气泡浮出速度理论的CO 2 气体保护焊焊缝中气孔倾向探讨 Discussion on the tendency of porosity in weld of CO 2 arc welding based on the theory of bubble escape velocity 孙咸 SUN Xian 1 first-author 太原理工大学焊接材料研究所 太原理工大学焊接材料研究所 Institute of Welding Consumables,Taiyuan University of Technology Institute of Welding Consumables,Taiyuan University of Technology CO 2 气体保护焊焊缝中气孔类型可以归纳为两大类（冶金反应型和析出型）,气孔的性质分别为CO气孔、氢气孔及氮气孔。气孔的形成由气泡生核、长大、逸出三个阶段组成。CO 2 气体保护焊对气孔的敏感性是该工艺方法冶金特性所决定的。在工艺影响因素中,对气孔倾向影响较大的主要是焊接电流、电弧电压、气体流量、电源极性及焊接速度"。焊接飞溅小与气孔倾向大"的不协调关系,与熔滴过渡形态及熔滴携带气体行为相关。严格控制焊材成分、母材成分及坡口清洁度是控制焊缝中气孔的必要条件,而采用正确的工艺参数、辅助工艺及操作技术则是控制气孔的充分条件。 The types of porosity in weld of CO 2 arc welding can be classified into two categories（metallurgical reaction type and precipitation type）,the natures of the porosity are CO porosity,hydrogen porosity and nitrogen porosity respectively.The formation of porosity consists of three stages of nucleation,growth and escape of bubbles. The sensitivity of CO 2 arc welding to porosity is determined by the metallurgical properties of the process. Among the process influencing factors,Welding current,arc voltage,gas flow rate,power polarity and welding speed are the main factors that affect the porosity tendency. The inharmonious relationship between "small welding spatter and large porosity tendency" is related to the droplet transfer modes and the gas carrying behavior of the droplet. Strictly controlling the compositions of welding consumables,base metal and groove cleanliness are the necessary conditions to control the porosity in the weld,and adopting correct process parameters,auxiliary process and operation technology are the necessary conditions to control the porosity. 焊缝中气孔 CO2气体保护焊 气泡浮出速度理论 气体氧化性 porosity in welds CO2 arc welding theory of bubble escape velocity gas oxidability TG441.7 2022-03-08 6 51