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Vacuum Heat Treatment Furnace

Vacuum Sintering Furnace

Vacuum Brazing Furnace

Research on vacuum annealing of titanium alloys

The heat treatment of titanium alloy is a process that changes the phase composition and organizational structure of the alloy through heating, holding and cooling, thereby improving its performance. An important basis for determining the process parameters of titanium alloy heat treatment is the transformation temperature of the B phase. The heat treatment of the alloy can be divided into vacuum annealing, solid solution treatment (quenching) and aging treatment.

Vacuum annealing

The purpose of annealing is to homogenize the structure and phase components, obtain uniform properties, improve plasticity, and eliminate internal stress formed during pressure processing, welding, machining, etc. Complete annealing is performed above the recrystallization starting temperature but below the transition temperature of phase B. Usually the annealing temperature is selected at 120 ~ 200C below the transition temperature of phase B. For incomplete annealing to eliminate stress, the temperature is generally chosen to be 150 ~ 250C below the recrystallization starting temperature. The annealing temperature of plates is lower than that of rods and forgings. Annealing of titanium alloys is generally performed in a non-vacuum state, but sometimes vacuum annealing is required to remove hydrogen or prevent pollution from harmful gases such as oxygen and nitrogen. The vacuum annealing temperature is generally 600~850°C, and the vacuum degree should be less than 0. 13Pa. This can make the hydrogen content in titanium materials less than 0.015%. In order to form a dense protective film on the surface of the titanium material after vacuum annealing, air should be injected into the furnace while the vacuum annealing is cooled to a temperature of 300~350°C.

Vacuum annealing furnace operating steps

A method for vacuum annealing titanium or titanium alloy materials using a low vacuum unit and gas protection, which is characterized by including the following steps:

1) Install a high-temperature-resistant gas pipe under the furnace cavity of the existing vacuum furnace. One end of the high-temperature-resistant gas pipe extends into the furnace cavity, and the other end of the high-temperature resistant gas pipe extends out of the furnace cavity and is connected to the protective gas bottle. The protective gas bottle outlet There is a pressure gauge;

2) According to the operating procedures of the vacuum furnace, turn on the water pump and air compressor, check that there is no air leakage or water seepage in each pipeline, then push the frame with titanium pipes installed into the furnace cavity, and lock the furnace door;

3) Turn on the low vacuum unit to evacuate the furnace cavity, then turn on the protective gas bottle switch to continuously fill the furnace cavity with inert gas. Use the inert gas and the low vacuum unit to cooperate with each other to ensure the vacuum in the furnace cavity and make the titanium or titanium Alloy materials are always in an inert gas protective atmosphere;

4) According to the vacuum furnace operating procedures, complete the heating, heat preservation and cooling processes. When the temperature in the furnace cavity drops below 100°C, turn off the protective gas cylinder switch and the low vacuum unit switch, and discharge the material.