When the hydrogen content in the titanium pipe is too high, the impact toughness and notched tensile strength will be reduced due to brittleness. Therefore, it is generally stipulated that the hydrogen content in titanium pipe fittings should not be higher than 0.015%. To reduce the absorption of hydrogen, fingerprints, wear marks, grease and other residues should be cleaned up before heat treatment. There is no water vapor in the heat treatment furnace. When the hydrogen content of titanium pipe fittings exceeds the allowable value, vacuum annealing is required for cleaning.
When the temperature is not higher than 540 degrees, the oxide film of the titanium pipe will not become much thicker, but at a higher heat treatment temperature, the oxidation rate will be accelerated, and the inner diffusion layer of the oxidized material will become a layer of pollution. The oxygen contaminated layer has a high brittleness ratio, causing cracks and damage to the surface of the part. The deoxidized pollution layer includes mechanical processing, pickling, chemical grinding and other methods. During heat treatment, on the premise of protecting the heat treatment, shorten the heating time as much as possible. It can also be carried out in a vacuum furnace or an inert gas furnace, which should properly avoid or reduce the pollution caused by the heating of the titanium tube in the air furnace.
Features of titanium pipe fittings:
- 1. Corrosion resistance of titanium pipe fittings. Titanium is a very active metal with a low equilibrium potential and a strong thermodynamic corrosion tendency in the medium. Titanium has good stability and corrosion resistance in various media such as oxidation, neutrality, and weak reduction.
- 2. Titanium pipe fittings have good heat resistance. It can be used for a long time at a temperature of 600 degrees or higher.
- 3. Non-magnetic, non-toxic, titanium alloy pipe is a non-magnetic metal that will not be magnetized in a large magnetic field.
- 4. Low elastic modulus, 57% steel.
- 5. Inhalation performance. Titanium fittings are active metals that can react with many elements and compounds at high temperatures.