Grade 7 titanium alloy argon arc welding process points of attention

Grade 7 titanium alloy Argon arc welding titanium alloy pipe welding is usually on-site all-position welding, the difficulty of welding than stainless steel pipe much higher than the titanium and its alloys above 400 ℃ weld zone must be protected, because of its chemical nature is particularly active, it is easy to absorb harmful gases, resulting in a decline in the performance of the material, and even cracks. So when welding should pay special attention to the following matters.
1, argon arc welding in the welding of titanium pipe and its titanium alloy pipe, welding material selection is basically the principle of equal strength, can not find a suitable welding material, can be used to cut from the base material to solve the problem; and argon selection will have a direct impact on the hardness and toughness of the weld, and on the welding cracks have a significant impact, so the requirements for the selection of (especially pure titanium) high purity argon gas (99.99%).

2, welding titanium tube cutting and rupture production should be used cold processing methods, shall not make it overheating and discoloration. In the bevel inside and outside the surface of not less than 20mm range with a grinding wheel or stainless steel wire wheel to polish out the metal luster, with a scraper to trim the bevel burr and then polished smooth, to avoid hanging on the cloth wire in the cleaning.
3, in titanium alloy welding when the quality of cleaning directly affects the welding cracks and porosity, usually the first use of pickling (3% HF + 35% HNO3 + H2O), and then rinsed with water, and finally dry, wipe with acetone or alcohol before welding. After cleaning the weld must be welded immediately, not more than 4h, or need to be re-cleaned. Cleaning can not use rubber gloves, should use white cotton gloves.