Development Of Activating Flux Of A-TIG Welding For Titatium Alloy

TIG welding is a common method for titanium alloy, however, the non-concentrated arc heat results in low penetration of single pass welding (≤3mm) and low welding efficiency. For medium-thick plate welding, this process require groove, multi-layer and multipass welding, so that the process become complex, the welding efficiency become low and welding costs increased. Therefore, TIG welding usually used in thin plate welding or used for rendering in multi-layer welding. As for the A-TIG welding, to eliminate the pore in the titanium alloy weld bead , Parton welding institute brush a layer activating flux above the surface of welding line before welding, found that the pore disappeared , Meanwhile ,the weld penetration was increased.Therefor , for increasing the weld penetration, A-TIG welding was extensive researched for various kinds of alloys.In the present paper ,by selecting 10 kinds of common halides and single substance such as MgF₂,NaF,MnCl₂,MgCl₂,Te,CrCl₃ et al as activating fluxes, surface layer welding is implemented for sample with the DCEN A-TIG welding process, influence of activating flux on weld penetration,weld width,arc shape and welding arc voltage are analyzed, and the experiment is optimally designed , so multi-component activating FT-S5 is developed, which owns good stability and high reliability in the titanium alloy A-TIG welding. On this basis, the effect of welding parameters on the weld penetration and weld width is studied as well, and the optimized A-TIG welding parameter for titanium alloy is gotten, the result suggests good weld shape without porosity or other defects. What's more, the influence of the activating flux quantity of FT-S5 on the weld penetration is studied and the best activating volume is obtained finally.A-TIG welding for titanium alloy is tested with FT-S5 activating flux, the influence of activating flux on tensile property,impact properties,hardness and decay resistance of welded joints are analyzed. Furthermore, by changing the arc length and excursion experiment of welding bead, the mechanism of increasing TC4 Titanium alloy weld penetration by activating flux is analyzed.The topic of A-TIG welding for TC4 titanium alloy has developped activating flux for engineering practice, it apparently will greatly improve the efficiency and quality of titanium alloy welding, which is of a wide application prospect and practical significance.