Vacuum Hardening

VACUUM HARDENING

Vacuum hardening is a type of heat treatment especially used for hardening tool or high-speed steels. Its difference from quenching & tempering is the heating and cooling media.

Heating is performed in a vacuum oxygen-free environment, so that neither scale, nor carburization or decarburization occurs on the part surface. The design of vacuum heat treatment furnaces is suitable for reaching high temperatures required for tool steel heat treatment.

Cooling is performed by applying high pressure with a gas that does not react with steel, such as nitrogen. The gas under high pressure is cooled inside the furnace and blown onto the part. By changing the flow direction, shape, and pressure of the gas, distortion can be minimized.

Precision control systems have enabled monitoring the surface and core temperatures of the part during the process and controlling the furnace according to these data. In this way, deformations due to dimensional changes occurring during heating and cooling have also become controllable.