2010 年 28 巻 4 号 p. 369-375
In order to clarify fume formation mechanism in arc welding, quantitative investigation based on understanding of interaction among the electrode, arc and weld pool is indispensable. A fume formation model consisting of a heterogeneous condensation model, a homogeneous nucleation model and a coagulation model has been developed and coupled with a TIG welding model. A series of processes from setting arc operation conditions to generation of metal vapor and fume formation from the metal vapor is totally investigated by employing this simulation model. This paper aims to visualize the fume formation process and clarify the fume formation mechanism theoretically through numerical analysis. Furthermore, the reliability of the simulation model was also evaluated through comparison of the simulation result with experimental result. As a result, it was found that the size of the secondary particle consisting of small particles with size of several nm which range like a chain reaches 300nm at maximum in helium TIG welding.