The oil level of vacuum heat treatment furnace heat treatment when the pressure of selection problem

The oil level of vacuum heat treatment furnace heat treatment when the pressure of selection problem

Vacuum quenching furnace in vacuum heat treatment furnace used for oil quenching heat treatment process, under low vacuum pressure and vacuum cooling capacity of quenching oil drops, for some steel, may reach the purpose of quenching. Therefore, before using the vacuum quenching furnace quenching to quenching indoor neutral or inert gas filling the high purity, create constant pressure on the oil, can realize fully quenching of steel and the surface of the light. Can get the same quenching hardness under atmospheric pressure and the minimum surface pressure is called the critical quenching pressure. The characteristics of critical quenching pressure and vacuum quenching oil and is related to the hardenability of steel.
  In the use of vacuum quenching furnace for low hardenability of steel quenching, should choose to air into the oil way after quenching. The oil level of the pressure should be higher than the critical quenching pressure. The general regulation about 5 x 104 pa, but should not be below 1.0 x 104 pa. For intermediate hardenability of steel should be adopted after filling into the oil in this way. On the surface of the oil pressure can be adjusted at about 1.0 x 104 pa, but not less than 5 x 103 pa. Good hardenability steel can take air or air quenching in the form of gas, can be after filling in the vacuum furnace heating chamber into the oil, can also be the first oil after aeration. Take air way when air pressure is available in first (2.5 ~ 5) x 104 pa range selected. In order to prevent and reduce the steam to enter and contaminate vacuum quenching furnace heating room, should choose the higher air pressure, gas should be used in the high purity of neutral or inert gas. After filling, translates to lower gas purity, pneumatic pressure can be lower. Adopt the way of inflatable for quenching is artifacts into the oil are not filling the neutral or inert gas before and after.