Titanium fittings are heat treated to remove residues

When the hydrogen content in the titanium pipe fitting is too large, the impact toughness and notched tensile strength will drop sharply due to embrittlement, so it is generally stipulated that the hydrogen content in the titanium pipe should not exceed 0.015%. In order to reduce the amount of hydrogen absorption, the parts should be free of fingerprints, rolling mill marks, grease and other residues before heat treatment, and there is no moisture in the heat treatment furnace. If the hydrogen content of titanium pipes exceeds the allowable value, it must be removed by vacuum annealing.

When the temperature does not exceed 540 degrees, the oxide film of the titanium pipe will not be significantly thickened, but at a higher heat treatment temperature, the oxidation rate will rapidly accelerate, and at the same time, the internal diffusion layer of the oxidized material is a pollution layer. The oxygen contamination layer has a high brittleness ratio that leads to cracks and damage on the surface of the part. There are mechanical processing methods, or chemical methods such as pickling, chemical milling, etc. for deoxidizing pollution layers. During heat treatment, the heating time should be shortened as much as possible under the premise of ensuring heat treatment. It can also be carried out in a vacuum furnace or an inert gas heating furnace. . The contamination of titanium pipe fittings when heated in an air furnace should be appropriately avoided or mitigated.