After
hardening, all steels show reduced plastic properties and unfavourable
stresses.
In order to
eliminate them, a heat treatment procedure is carried out, involving heating
the previously hardened material, heating and cooling it in order to obtain the
optimal structure and properties.
We offer
low, medium, and high tempering in the temperature range of 180-650°C. It is
possible to carry out the processes in the presence of shielding gas, and in
the case of highly personalized requirements for the highest purity, the
implementation of the vacuum tempering process.
It involves
heating the previously supersaturated alloy to a temperature lower than the
limit of solubility, heating at this temperature and cooling it down. During
the aging process, the excess component in the supersaturated solid solution is
released in the form of highly dispersed phases.
In some
cases, the aging involves intermediate phases and Guinier-Preston zones, in
which they segregate atoms dissolved in the solvent lattice.
Aging
causes strengthening, manifested by an increase in strength properties and a
decrease in plastic properties.
When the
temperature is too high, the aging effect occurs, consisting in coagulation of
the precipitates and the loss of their coherence, which does not increase the
hardness in relation to the supersaturated state, but on the contrary - reduces
it.
Sometimes
aging occurs at room temperature, then it is called spontaneous aging.
Aging can
also be an undesirable process, e.g., in deep drawing sheets and boiler steels,
as it reduces plastic properties and increases brittleness.
A method of
heat treatment of the material, which usually involves heating the steel to a
specific temperature, heating it at this temperature and cooling it in order to
obtain structures close to the equilibrium state.
We
distinguish between recrystallization annealing, homogenization, stress relief,
complete, isothermal and spheroidizing annealing.
In the
field of annealing, we carry out orders from a wide range of services.