The Processes Performed with Heat Treatment Furnaces

The Processes Performed with Heat Treatment Furnaces

The term heat treatment covers a variety of controlled processes that are used to alter a material’s physical and chemical properties. Heat treatment furnaces are used to achieve these processes, which involve extreme heating or cooling to achieve their desired reaction.

This blog post will outline some of the heat treatment processes that can be achieved with heat treatment furnaces.


Heat Treatment Processes


Annealing is the process of heating up and maintaining a material at a specific temperature and then cooling it at a suitable rate. The main use of this process is to soften a material for improved machinability, cold working or to enhance electrical or mechanical properties.

Heat treatment furnaces performing annealing will use different maximum temperatures and cooling rates depending on the application and the required reaction.

When annealing is used to only remove or reduce the internal stresses of a material the process is called stress relieving. This is usually achieved by heating a material below the lower critical temperature followed by a uniform cooling.


Heat treatment furnaces that perform quenching cool materials at a rapid rate to produce the desired results. This process will often produce a harder metal in ferrous alloys and a softer metal in non-ferrous alloys.

Quenching is used with materials that require high resistance to deformation and corrosion, such as blades and storage tanks.


Tempering is a process that is often used after a material has been quenched. A heat treatment furnace tempering a material would help to reduce the brittleness and remove any stresses caused by quenching.

In this process, the steel is heated to a specific temperature and then cooled. If the material is heated to 300 – 750oC troostite is formed, a softer yet tougher structure. A structure called a sorbite is formed if the material is heated to a temperature of 750 – 1290oF, which is weaker than troostite but more ductile.

Selective Heat Treating

This process is where a heat treatment furnace is used to alter the properties of only a portion of a material. It can be used to produce improved strength, wear resistance or impact resistance where it is required in certain sections of a material.

The process can be achieved by tempering different areas at different temperatures, heating rapidly in a localized area and then quenching and thermochemical diffusion. Case hardening, induction hardening, and flame hardening are all examples of selective heat treating.

Heat Treatment Furnaces from Thermcraft

Thermcraft have a range of heat treatment furnaces that perform the processes mentioned above and many others. Choose from our standard range of furnaces or if something more specific is required we are able to manufacture custom furnaces.

Please contact us if you require any more information about heat treatment furnaces or would like to request a quote.