Tantalum has a boiling point of 5427 ℃ and a melting point of 2996 ℃, making it a refractory metal. Its melting point is higher than other commonly used metals. Tantalum reacts with oxygen at 300 ℃ in air, with nitrogen at 700 ℃, with hydrogen at 350 ℃ in hydrogen containing gas, and with nitrogen at 300 ℃ in ammonia gas, resulting in brittle compounds. Therefore, if tantalum equipment and containers come into contact with air during operation, the operating temperature should generally not exceed 250 ℃. If they cannot come into contact with air or other environments, they can only be considered for use at higher temperatures. The welding and heat treatment of tantalum should be carried out in vacuum or under inert gas protection, that is, the thermal process above 300 ℃ should be carried out under vacuum or inert gas protection. Tantalum is commonly used for inert gas shielded welding, and the purity of argon gas should not be lower than 99.999%. Not only should the welding pool be protected by inert gas, but also when the welding seam and heat affected zone during cooling are above 250 ℃, inert gas protection should be used. Therefore, protective towing covers are required. It is more suitable to stop supplying inert gas when the temperature drops below 200 ℃. It should be ensured that the welded joint and the surface of each weld seam are silver white or light yellow. Light blue should be ground off and there should be no dark blue, gray white, or white powder present.

Tantalum plate is mainly used as a corrosion-resistant material, and Ta2O5 thin film is generated on the surface of tantalum, which has good corrosion resistance. Generally speaking, tantalum has better corrosion resistance than titanium, zirconium, and niobium, and can be considered as an engineering material with better corrosion resistance. Tantalum often exhibits excellent corrosion resistance in strong corrosive media such as nitric acid, aqua regia, hydrochloric acid, phosphoric acid, and organic acids. However, it cannot be considered that tantalum can resist corrosion in any corrosive medium, such as fuming sulfuric acid, hydrofluoric acid, hydrosilicic acid, fluorosilicic acid, fluoroboric acid, sodium hydroxide, potassium hydroxide, potassium nitrite, aluminum chloride, aluminum fluoride, chlorine, etc. at certain temperatures and concentrations Bromine (in methanol) and other medium solutions have been used or tested for poor corrosion resistance or poor corrosiveness. Tantalum and tantalum alloy pressure processing materials can be manufactured using vacuum arc or vacuum electron beam melting grades and powder metallurgy methods. Due to the unstable mechanical properties, low plasticity, and poor welding performance of powder metallurgy products, they are generally no longer used in pressure vessels, but only in fluid components of fluid machinery.

Tantalum and tantalum alloys have been widely used in pressure vessels, but there is no specific content in the official pressure vessel standards and specifications of various countries. The main application of pressure vessels is pure tantalum, which has good corrosion resistance and plasticity. Ta-2.5W and Ta-10W tantalum alloys are only used when high strength is required.

Oxygen, nitrogen, hydrogen, and carbon in tantalum can form interstitial solid solutions in tantalum. When the content exceeds the solubility, a second phase will appear, reducing the plasticity of tantalum. Adding tungsten to tantalum increases its melting point and high-temperature strength.