Vacuum Furnace FAQ

---

1. What are the main parts of the vacuum furnace?
Melting chamber, casting chamber, vacuum system, power system.

2. What is alloying?
Alloying refers to the process of adding metal materials during the smelting process and adjusting the alloy composition according to the steel type.

3. What is the reason for the vacuum does not go up in the vacuum furnace?
1) Furnace body leakage;
2 )Vacuum pump pumping capacity is insufficient;
3 )High gas content of the molten steel with large gas discharge
4 )The equipment has water leakage or oil leakage.

4. What are the maintenance issues for the vacuum system during the smelting process?
1 ) Quality of vacuum pump oil, oil level is normal;
2 )The filter is switched normally;
3 )The isolation valves are sealed properly.

5. How to improve the high temperature performance of the crucible?
1)Reducing the ratio of CaO and CaO/SiO2 in the MgO sand to reduce the amount of liquid phase and increase the temperature at which the liquid phase is generated.
2) Improve the stability of crystal grains.
3 )The sintered layer is in a good recrystallization state, so as to reduce the porosity, reduce the grain boundary width, and form a mosaic structure, which constitutes a direct combination of the solid phase and the solid phase, thereby reducing the harmful effects of the liquid phase.

6. What are the commonly used adhesives for ramming crucibles?
1) Organic substance: dextrin, pulp waste liquid, organic resin, etc.;
2 )Inorganic substances: water glass, brine, boric acid, carbonate, clay, and so on.

7. What is the task of the melting process?
Melting, degassing, removal of low-melting harmful metal impurities and non-metallic inclusions, adjusting the temperature of the alloy liquid, and placing it under sufficient vacuum to create conditions for the refining .

8. What preparations do you need to do before melting?
1 )The equipment must be inspected before melting, including furnace body, vacuum, electrical appliances, machinery, water cooling, temperature measurement, pouring, etc.
2 )The furnace must have suitable vacuum and air leakage rate during smelting;
3 )Raw materials meet the requirements of technical regulations, and the ingredients are accurate;
4) Crucibles have good knotting and sintering quality;
5 )Develop a suitable process.

9. What measures should be taken to volatilize harmful impurities?
In order to volatilize the essential impurities under vacuum, it is necessary to increase the vacuum in the furnace as much as possible.

10. What are the characteristics of vacuum casting?
1 )The molten steel is particularly fluid under vacuum;
2) Molten steel and ingots and electrodes poured under vacuum are extremely slow to dissipate heat;
3 )The molten steel poured into the mold under vacuum is continuously released with the cooling and solidification of the molten steel;
4 )The molten steel is directly injected into the mold without the steel drum.