The surface quality of welded parts and titanium welding wire has a great influence on the mechanical properties of welded joints. Iron plate and titanium welding wire can be mechanically cleaned and chemically cleaned.
The welding parts with low quality requirements or difficult pickling according to mechanical cleaning can be wiped by fine sandpaper or stainless steel wire brush, but it is better to use hard alloy yellow to scrape the titanium plate and remove the oxide film.
Chemical cleaning. The sample and the wire can be acid washed before welding. The acid lotion can be used as hf5% + hno335% water bath. After pickling, rinse with clean water and dry immediately after welding. Or use acetone, ethanol, carbon tetrachloride, methanol and other materials to wipe the groove of the titanium plate and its two sides (within 50mm of each other), the surface of the welding wire, and the parts of the clamping device that are in contact with the titanium plate.
The choice of welding equipment titanium and titanium alloy gold tungsten plate argon arc welding should choose the dc argon arc welding power source with the characteristics of falling outside and high frequency arc induction, and the delayed gas delivery time should not be less than 15 seconds, so as to avoid the welding to suffer from oxidation and pollution.
Purity of argon welding material selection should be not less than 99.99%, the dew point in below 40 ℃, impurities total quality score & lt; 0.001%. When the pressure in the argon gas cylinder drops to 0.981MPa, the use shall be stopped to prevent the quality of the welded joint from being affected. In principle, titanium wires with the same composition as basic metals should be selected. Sometimes, in order to hold high weld metal plasticity, welding wires with lower strength than basic metals can be selected.
Gas shielded welding and temperature titanium tube joints in welding is land, in order to prevent the welded joint at high temperature are contaminated with harmful gases and elements, must be the necessary welding butt welding area and weld protection and temperature control, its temperature should be below 250 ℃. The main methods of protection and temperature control are as follows: first, add protective gas cover to the surface weld seam; Second, the welded pipe will be filled with protective gas. The shielding gas is argon gas with a purity of 99.99% or greater. The flow rate of protective gas should meet the requirement of welding technology
