The protection of vacuum heat treatment in multi-purpose furnace

For many materials heated in the non vacuum furnace, in addition to the formation of oxides, hydrides nitrides, the materials heated in the non vacuum furnace will absorb gas diffuse to the interior, which will seriously deteriorate the performance of the materials. These disadvantages, such as oxidation, reduction, decarbonization, carburization, inhalation even corrosion, are sometimes unavoidable in controlled atmosphere furnace salt bath furnace, while vacuum heat treatment furnace can avoid these disadvantages at many times.

Vacuum heat treatment is essentially carried out in a very thin vacuum furnace atmosphere. The gas analysis in the vacuum furnace shows that the residual gases in the vacuum furnace are H2Q, O2, CO2, oil other organic vapor. Because the content of these gases in the vacuum furnace is very small the partial pressure is very low, it is enough to make the treated material produce oxidation, reduction, decarburization, carburization other reactions, so the chemical composition of the material surface the original surface brightness can remain unchanged. There are two characteristics of high vacuum in vacuum furnace:

1. The chemical activity of high vacuum atmosphere is very low, so the reaction between gas phase solid phase, such as oxidation, reduction, decarburization carburization, will be affected when using vacuum electric furnace for heat treatment;

2. The high vacuum atmosphere in the multi-purpose furnace makes the gas volume increase rapidly, which can make the material release dissolved gas oxide to decompose. Because of these two characteristics of high vacuum atmosphere in vacuum furnace, the partial pressure of oxygen is very low the oxidation is inhibited. Therefore, in order to achieve the goal of no oxidation, the partial pressure of oxygen in vacuum furnace must be lower than the decomposition pressure of oxide.