ルチール系フラックスコアードワイヤによるFCA溶接の溶融池シミュレーションモデル

抄録

Arc welding process is indispensable technology in various fields of industry. In order to develop a high quality and high productivity welding process, it is important to control the welding process. In flux cored arc welding (FCAW), a flux cored wire (FCW) is used. The FCW is composed of a metal sheath and a central flux core. There are various types of the flux such as a deoxidizing agent, a stabilizer of the arc plasma, a slag-forming agent and so on. When the TiO2-based FCW is used, the slag covers the weld metal surface. The appearance of weld metal after the welding process is beautiful and it can be applied to all-position welding, but the phenomena during the welding process is not clear completely. In this study, to make clear the welding phenomena, a numerical simulation model of weld pool phenomena in welding process using TiO2-based FCW is constructed. The model calculates fluid flow in the weld pool and the distributions of the metal and the slag are calculated by VOF method. The model is applied to the vertical upward welding. In case of the solid wire, the molten metal flows downward strongly and forms humping bead. On the other hand, in case of the TiO2-based FCW is used, the slag covers the molten metal surface and the strong downward flow is prevented, and sound bead is formed. The molten metal flow at the surface is very important to determine the bead formation phenomena. In addition, the interfacial tension and the melting temperature of the slag are important to determine the distribution of the slag at the molten pool surface and bead formation phenomena.