The precipitation hardening process is used for mainly non-ferrous steels and austenitic steels that do not show allotropic transformations. This process consists of solution heat treatment and aging.
The process of thorough hardening consists of combination of hardening and high tempering.
We have the following technologies:
– in a vacuum atmosphere with gas quenching (max 25 bar abs)
High tempering processes are carried out in air or nitrogen atmosphere.
We can distinguish typical, gradual, isothermal, surface finish hardening. Depending on the type of hardening, the steel microstructure is martensite or bainite.
The annealing process involves heating the material to a predetermined temperature, soaking at this temperature and slow cooling under a protective atmosphere or in air. Depending on the process parameters, we can distinguish between homogenizing, complete, normalizing, spheroidizing, recrystallizing and stress relieving annealing.
In the scope of annealing, we offer annealing with:
– slow cool in air atmosphere
– slow cool under vacuum
– slow or forced cool under nitrogen or argon
Tempering is a heat treatment process consisting in heating the previously hardened steel to a certain temperature, withstanding and slow air cooling. The purpose of tempering is to remove the stresses created during hardening, to change the physical properties and, above all, to increase impact resistance at the expense of reduced hardness.
We can distinguish three types of tempering:
– Low temperingat 150-250°C,applied in order to reduce hardening stresses. It does not significantly influence hardness reduction.
– Average temperingat 250-450°C, applied in order to provide significant strength and elasticity while maintaining sufficient resilience and ductility.
– High tempering at 450-Ac1, applied in order to significantly reduce hardness and obtain good flexural properties.