At present, flux or metal cored wires are widely used in iron-based materials for flux cored arc welding in order to reduce the cost of welding production. However, the development of flux or metal cored wire for titanium materials, which are widely used in the petrochemical, power plant and marine vessel fields, has not been done yet, and development is required. In this study, manufacturing process of titanium alloys flux-metal cored wire for gas tungsten arc welding was investigated by FEM simulation and experimental analysis. FEM simulation of tube welding process was carried out with initial three preform-types (butt tube, overlap tube and welded tube). In the FEM simulation results, tube welding process using initial welded tube was evaluated to cause cracking of the specimen during the process. In actual making process of titanium alloys flux-metal cored wire for gas tungsten arc welding, overlap-type tube was evaluated to be the most suitable initial preform shape. In addition, it was confirmed that the filling ratio of the flux-metal was maintained uniformly at over 70%.

The annealing condition dependence on the weldability of Ti-6Al-4V ELI alloy was studied by means of the tensile test, hardness and microstructure analysis. The Ti-6Al-4V ELI plate with 1 mm plates were joined by the fiber laser welding under 2 kw laser power and 100 mm/s welding speed condition. Various PWHT (Postweld heat treatment) conditions were used to improve the formability of the welded titanium alloy. The results showed the solution treatment for the PWHT contributes on the homogeneous strength distribution from fusion zone to base material. This PWHT conditions were expected to minimize the degradation of the formability caused by the welding.