The characteristic of
titanium alloy welding is not only to protect the metal on the back of the molten pool, but also to protect the heat affected zone, or even the close seam zone from oxidation. Because titanium load above 350℃ will have a violent chemical reaction with oxygen and water vapor in the air, the entry of O, N and H will sharply reduce the plastic and fatigue properties of welded joints. Therefore, the best way to weld titanium alloys is to do so in a vacuum or inert gas chamber.
TA15 titanium alloy belongs to the medium strength (750 ~ 1000MPa), similar titanium alloy such as: TC1, TC4, TC6, bt5-1, CT5, etc., all the medium strength titanium alloy has good weldability and thermal stability.TA15 titanium alloy is an alloy based on ti-al-zr-mo-v system. Its nominal composition is: ti-6.5 al-2zr-1mo-1v.The main strengthening mechanism of this alloy is through the solid solution strengthening of a stable element Al, adding medium element Zr and stable element Mo and V of beta can improve the process performance.TA15 titanium alloy can work for 3000h at 500℃.It can work for 6000h under 450℃, which is mainly used in the field of aviation at present.TA15 not only has good weldability, but also can be welded in various ways. And can be welded with various deformation titanium alloy and casting titanium alloy, here introduced vacuum filled argon manual argon arc welding.
Before titanium alloy welding, the surface of welding parts must be strictly cleaned. Titanium alloy TA15 is performed vacuum argon filled manual argon arc welding, and the welding wire used is ta15-1 under the condition of withdrawal. Plate thickness 5.0mm, 45°V groove opening; Opening 45° double-v groove with thickness of 8mm;No beveling for automatic welding plate thickness 5.0mmTA15.
Manual TIG welding is performed in a vacuum argon filled box. The vacuum of the welding box is 1.33pa before welding, and then argon is passed to 0.103mpa before welding. Automatic welding is local protective argon arc welding. During welding, the arc is started from the process backing plate, and the arc is closed by attenuating welding current to fill the arc pit. The protective gas will continue to be provided within 3min after solidification.
