R. Liu, P. Zhang, Nanjing University of Aeronautics and Astronautics, Nanjing, China
Weld droplet transfer behaviors of mixture gas-shielded basic flux-cored wire have an important effect on the processing property of flux-cored wires. Droplet transfer formations, arc shapes and welding spatter rate were investigated by high speed photography, water collecting droplets and spatter tests. The effect of MgO on droplet transfer formations and welding arc shapes of flux-cored wire were summarized. The results showed that when MgO was about 20%~25%, the droplet transfer was steady with relatively small molten droplets and welding electric arc was bright, soft, and presented clock-like shapes. In this case, favorable welding process feature was acquired. When MgO was more than 25%, the metal transfer turned into globular repelled transfer and welding spatter became great. The phenomenon of arc moving from inside to outside was serious and the arc was relatively unstable with bigger spatters.
Summary: Droplet transfer behaviors and welding spatter of FCW are influenced by manay factors and MgO is one of them and the paper presents its effects in detail.
