When the hydrogen content in the titanium pipe member is too high, the impact toughness and the notched tensile strength are reduced by brittleness. Therefore, it is generally prescribed that the hydrogen content in the titanium pipe member should not be higher than 0.015%. In order to reduce the absorption of hydrogen, fingerprints, wear marks, grease and other residues should be cleaned before heat treatment. There is no water vapor in the heat treatment furnace. When the titanium tube has a hydrogen content higher than the allowable value, vacuum annealing is required.
When the temperature is not higher than 540 degrees, the oxide film of the titanium pipe does not become much thicker, but at a higher heat treatment temperature, the oxidation rate is accelerated, and the inner diffusion layer of the oxidized material becomes a layer of pollution. The oxygen-contaminated layer has a high brittleness ratio, causing cracks and damage on the surface of the part. The deoxidation contaminated layer includes mechanical processing, pickling, chemical polishing, and the like. When heat treatment, under the premise of protective heat treatment, the heating time should be shortened as much as possible. It can also be carried out in a vacuum furnace or an inert gas furnace, and the contamination caused by the heating of the titanium pipe fittings in the air furnace should be appropriately avoided or reduced.
Titanium fittings features:
1. Corrosion resistance of titanium pipe fittings. Titanium is a highly reactive metal with a very low equilibrium potential and a strong tendency to thermodynamically corrode in the medium. Titanium has good stability and corrosion resistance in various media such as oxidation, neutrality and weak reduction.
2. Titanium pipe joints have good heat resistance. It can be used for a long time at 600 degrees or high.
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 modulus of elasticity, 57% steel.
5. Inhalation performance. Titanium fittings are an active metal that reacts with a wide range of elements and compounds at elevated temperatures.