How do you select the oil surface pressure

How do you select the oil surface pressure

In the use of a vacuum quenching furnace 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 to quench indoor filling the high purity of neutral or inert gas, in order to create constant pressure on the oil, so that you can fully steel quenching and get the surface of the light. The critical quenching pressure is the lowest level of liquid pressure at the same time as the same hardening hardness under atmospheric pressure. The characteristics of critical quenching pressure and vacuum quenching oil are related to the hardening of steel.
When hardening of hardened steel by vacuum quenching furnace, it is necessary to inflate and then harden into oil. The pressure in the oil is higher than the critical quenching pressure. In general, you can adjust to about 5 times 104Pa, but not below 1.0 x104pa. For some medium hardened steel, it also requires the use of the first gas and then the oil in the process of quenching. The pressure of the oil can be adjusted to about 1.0 times 104Pa, but not for less than 5 times 103Pa. For some good quenching hardness steel can choose air or air in this way, if with the method of gas, then choose inside. In order to prevent and reduce the pollution of the steam entering and vacuum quenching furnace heating chamber can choose to use higher air pressure, the gas should be adopted by the high purity of the inert or neutral gas. If you use a post-inflation method, you can choose a gas that is low in purity, and the pressure can be lower. If the method is not inflated, then the workpiece does not need to be inert or neutral until the oil is in the oil.