Tantalum is a refractory rare metal with high density, high melting point, small expansion coefficient, and good high-temperature strength and processing performance. Except for hot sulfuric acid solution, tantalum has very good corrosion resistance in mixed media of most industrial acids, so tantalum is an important corrosion-resistant material for chemical and petrochemical equipment.
Tantalum has stable performance at room temperature. It can be directly combined with non-metallic elements when heated. When tantalum is heated to 200-300 ℃, it will be slightly oxidized, and it will rapidly oxidize when heated to above 500 ℃. At high temperatures, tantalum will absorb hydrogen, oxygen, nitrogen, and other gases from the environment and form brittle compounds. A small number of gas impurities can significantly affect the mechanical properties and corrosion resistance of tantalum.
For cost considerations, the design thickness is often chosen to be thinner. In addition, due to the huge difference in melting point between tantalum and steel, tantalum and steel will undergo eutectic reaction at high temperatures to form Fe2Ta intermetallic compounds, which is very unfavorable for the welding of tantalum-steel clad plates or tantalum linings, especially as the thickness of tantalum decreases. Then, the welding difficulty is more obvious. The accumulation of thin-plate tantalum welding experience and the continued mastery of welding characteristics will play a role in promoting the improvement of tantalum equipment manufacturing quality in the future.
Due to the welding characteristics of tantalum materials and the structural characteristics of tantalum-lined equipment, it is decided that not only strict process measures should be taken in the blanking, groove processing, forming, and other processes, but also the welding environment, pre-welding cleaning and welding protection must be satisfied. Special requirements for tantalum welding. First, the welding site is an independent area to keep the environment clean to prevent smoke, oil, and wind disturbance; secondly, the welding groove and the 30mm area on both sides of the welding groove are subjected to strict mechanical cleaning and degreasing treatment, and welding is performed immediately after cleaning; Argon gas with > 99.99%, dew point ≤-50℃ and special protective drag cover plus double-sided ventilation protection to avoid oxidation.
Baoji Yusheng Metal Technology Co., Ltd. mainly supplies tantalum, niobium, tungsten, molybdenum, titanium, zirconium, nickel and other rare metals, non-ferrous metals, precious metals, and alloys, we have excellent products and professional sales and technical team, if you are interested in our company's tantalum plate products, please feel free to contact us.
