What is Vacuum Hardening? What are the advantages?

Vacuum hardening, also known as vacuum heat treatment, can be explained as the hardening and tempering processes carried out after the atmospheric pressure in the furnace is removed before the process and with the help of vacuum pumps. It is a frequently preferred process especially for hardening tool steels, high speed steels and martensitic stainless steels.
What are the advantages of heat treatment in vacuum furnaces?
Thermal treatments in vacuum furnaces have many advantages. However, if we need to briefly collect them under one or two headings, it is possible to list them as surface cleanliness, repeatability, homogeneity, distortion and environment. Surface Cleaning During the process; Since there is no air, inert gas or chemical salts inside the furnace that can create scale or residue, the material surface is clean and shiny, and this feature ensures that no further cleaning process is required. Because the materials leave the process clean and bright. Repeatability The processes carried out in the vacuum furnace are carried out completely under computer control and every process is recorded. If desired, the same operation can be repeated exactly the same way, and this is important in that it allows the operations to be performed in the same way. Homogeneity Since all vacuum firing processes are carried out in a closed and airless environment, heat distribution can be distributed homogeneously throughout the material. In this way, no large variability is observed between the hardness and microstructure of similar materials processed and charged at the same rate. Distortion: Almost all operations performed in vacuum furnaces; Since the furnace environment, heating and cooling times, and temperature control are very sensitive and can be controlled, there are no problems such as deformation or distortion of the materials after heat treatment. This risk is quite low compared to other hardening environments. Environment Vacuum baking is a completely environmentally friendly process, as no chemicals or gases harmful to nature are used during the process, and it protects environmental health and the ozone layer. In addition, it would not be wrong to say that it is an environmentally friendly process, as no operations that could be harmful to nature are carried out during these processes.