When the hydrogen content in the titanium pipe is too much, the impact toughness and notched tensile strength will drop sharply due to the brittleness, 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, fingerprints, rolling mill marks, grease and other residues should be removed before heat treatment. There is no moisture in the heat treatment furnace. If the hydrogen content of the titanium pipe 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 fittings will not be significantly thickened, and at higher heat treatment temperatures, the oxidation rate will rapidly increase, and at the same time, the internal diffusion layer of the oxide material will become a pollution layer. The high brittleness ratio of the oxygen contamination layer causes cracks and damage on the surface of the part. There are mechanical processing methods for the deoxygenated pollution layer or chemical methods such as pickling and chemical milling. During the heat treatment, the heating time should be as short 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 pollution caused by the titanium pipe fittings being heated in the air furnace should be appropriately avoided or reduced.
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