How to carry out the picking and discharging of vertical atmosphere tube furnace?
Powder sintering under sub-atmospheric pressure conditions.
The main advantages of vacuum atmosphere furnaces are:
(1) The adverse effects of harmful components (water, oxygen, nitrogen) in the atmosphere on the product are reduced. For example, it is quite difficult to reduce the water content in the electrolytic hydrogen to a dew point of -40°C, and as long as the vacuum degree reaches 133Pa, it is equivalent to a dew point with a water content of -40°C. And it is not difficult to obtain such a degree of vacuum.
(2) Vacuum sintering can be used for materials that are not suitable for reducing or inert gas as a protective atmosphere (such as sintering of active metals), or materials that are prone to decarburization and carburization.
(3) Vacuum can improve the wettability of the liquid to the solid phase, which is conducive to shrinking and improving the structure of the alloy.
(4) Vacuum sintering helps to remove impurities such as silicon, aluminum, magnesium, calcium or their oxides, and plays a role in purifying materials.
(5) Vacuum is beneficial to remove adsorbed gas, residual gas in pores and reaction gas products, and has a significant effect on promoting shrinkage in the later stage of sintering. For example, the porosity of cemented carbide sintered in vacuum is significantly lower than that of cemented carbide sintered in hydrogen.
(6) The temperature of vacuum sintering is lower than that of gas shielded sintering. For example, when sintering cemented carbide, the sintering temperature can be reduced by 100-150 °C. This is beneficial to reduce energy consumption and prevent grain growth.
During vacuum sintering, metal volatilization loss often occurs. For example, the volatilization loss of cobalt occurs when cemented carbide is sintered. By strictly controlling the degree of vacuum, even if the pressure in the furnace is not lower than the vapor pressure of the sintered metal components, the volatilization loss of metals can be greatly reduced or avoided. Another problem with vacuum sintering is the decarburization of carbonaceous materials. This mainly occurs in the heating stage. Oxygen, moisture in the residual gas in the furnace and oxides in the powder can react with the combined carbon in the carbide or the free carbon in the material to generate carbon monoxide which is extracted with the furnace gas. . The decarburization of carbonaceous materials can be solved by increasing the carbon content in the powder and controlling the degree of vacuum.
In order to improve the heating speed and furnace temperature uniformity in the vacuum sintering process, an appropriate amount of gas (inert gas or hydrogen) can be introduced in the initial stage of sintering. The cooling rate of vacuum sintering can also be improved by using the circulating gas cooling method. In order to prevent the forming agent from contaminating the vacuum equipment system during sintering, the compact should be pre-fired before vacuum sintering to exclude the forming agent.
In powder metallurgy, vacuum sintering is mainly used for sintering active metals and refractory metals beryllium, thorium, titanium, zirconium, tantalum, niobium, etc.; sintering cemented carbides, magnetic alloys, tool steels and stainless steels; A compound that reacts with gases such as nitrogen and carbon monoxide.
1. Control accuracy: ±1°C Furnace temperature uniformity: ±1°C (depending on the size of the heating chamber).
Open-type tube atmosphere furnace 2. Easy to operate, programmable, PID self-tuning, automatic heating, automatic heat preservation, automatic cooling, no need to be on duty; can be equipped with computer communication through the computer to operate the electric furnace (start the electric furnace, stop the electric furnace, pause the heating, Set the heating curve, heating curve storage, historical curve, etc.), the software is free, see: Computer Control System.
3. Fast heating (the heating rate can be adjusted from 1°C/h to 40°C/min).
4. Energy saving (the hearth is made of imported fiber, resistant to high temperature and rapid heat and quench)
5. The furnace body is finely sprayed, resistant to corrosion, acid and alkali, and the furnace body and the furnace are isolated by air-cooling. The temperature of the furnace wall is close to room temperature.
6. Double circuit protection (over temperature, over pressure, over current, segment couple, power failure, etc.)
7. The furnace material is imported refractory material, which has good thermal insulation performance, high temperature resistance, and rapid cooling and rapid heating resistance.
8. Temperature category: 1200℃-1700℃, and can also be customized according to your requirements.