Tempering is a necessary process after every steel hardening. It removes stresses which result from heat or heat-chemical machining and allows the workpieces to achieve the required hardness. The process consists of heating the steel material several times and then cooling it. Vacuum tempering does not oxidize the components.
Depending on the temperature, we can distinguish:
– low tempering, used to remove the hardening stresses. It does not change the hardness of the steel obtained during the hardening process.
– medium tempering, used to temper springs. The result is a change in the crystalline structure of steel, which reduces brittleness while retaining hardness and elasticity.
– high tempering, done to increase the resistance of steel to high amplitude variable loads.
Heat treatment of metal is necessary to obtain the desired properties. Steel hardening is not the last process to be applied to the material. You still need professional tempering, which is done in a specially designed device. This gives the metal structure the necessary balance and thus superior hardness.
The process is not complicated or particularly time-consuming. It takes about 2 hours, during which the material is exposed to high temperatures under certain conditions. Tempering steel requires it to be heated up to 150-650şC. The metal is then cooled in the furnace by using tempering oil and similar preparations. Only then can the material be considered suitable for use.
It is worth noting that one of the effects of metal tempering is the breakdown of martensite. This creates cementite grains. In addition, secondary hardness occurs in high alloy steel. This is ideal for heat machining of tools.
There are several methods of tempering. We realize them all in our machinery park thanks to advanced technologies. So you request us to do any project that involves tempering of metals in low, medium, and high ranges. The differences between them largely depend on the temperature used. They are therefore suitable for different types of components.
Low tempering is used to give tool steel a suitable level of hardness. The method reduces the self-stresses while maintaining the high hardness resulting from the hardening process. It is carried out at temperatures between 150ºC and 350ºC.
Medium tempering results in changes in the crystalline structure of steel. It is therefore ideal for spring steels as it maintains the material’s original elasticity and plasticity. It also becomes less brittle. This method needs the material to reach temperatures between 300ºC and 500ºC and the material hardness is typically around 45 HRC. Examples of products which require this kind of metal tempering are springs and parts of automatic weapons.
The last method – high tempering, is carried out at temperatures exceeding 500ºC. The result is an increase in material resistance to high amplitude variable loads. In addition, steel is afterwards suitable for machining, as its hardness will be reduced.
The achieved benefits depend on the chosen method and its parameters. The general advantages include high durability, hardness and ductility. It should also be mentioned that tempering metals results in increased ductility, impact toughness and machinability. This is useful for further machining and for trouble-free operation in difficult conditions. This is why high temperature steel tempering is something worth doing after steel hardening.
The service we offer meets all standards and norms. It is also effective and efficient. We would like to point out that the vacuum tempering done by our company does not cause oxidation of the components. Therefore, they can be applied to even the most advanced projects.
We encourage all those interested in our services to contact us by telephone or email. We will be happy to answer any questions regarding steel tempering and offer the best solution for the customer.