BILBAINA DE TRATAMIENTOS
Cementation is a treatment that is intended to modify the chemical composition of the surface layer of the steel carbon enriching , in order to get pieces of low hardness acquire core surface high hardness.
The steels used in the cementing contents are generally below 0.25% carbon and by heat treatment of carburizing is achieved with a surface layer 0.70 % to 1.10% of carbono.Un temple gives back the surface layer hardness levels above 60 HRc , keeping the core good toughness.
THE ESSENTIAL PURPOSE OF CEMENTING IS HARD TO GET PARTS WITH HIGH SURFACE HIGH TOUGHNESS IN THE CORE.
– The surface carburizing
– Temple back and tempering / s to ease tensions temperate parts
Carbon enrichment of the surface layer of the parts is performed by heating these fuel among at temperatures between 870 º C and 950 º C. The duration of this heating is related to various parameters of which the most important is the carburized layer depth desired.
The phenomenon of the carburetor is divided into two parts:
1. ª transfer carbon atoms from a cementitious product pieza.Se surface is chemical reactions in which the temperature, the type of cement and steel chemistry are critical factors.
2. ª The spread of these carbon atoms from the surface toward the interior of the pieces, the preponderant factor being temperature and having little importance both cementing medium such as steel composition.
Carbon potential, which is very important from the viewpoint will cementing is the carbon content of a carbon steel in equilibrium with the cementitious product at a given temperature.
The operation that always follows the cementation of the pieces is the temple, which can be performed in three different modes: Temple direct, simple and temple temple twice.
Finally, the previously hardened components are subjected to a tempering at low temperature (between 100 ° C and 250 ° C) in order to reduce tensions created by resilience in the formation of martensite tetragonal.
The primary purpose of cementing is to obtain parts with high surface hardness and high toughness in the core.
The main advantage cementation has on other surface treatments lies in the depth of layer we can get, up to 3 mm as a general rule, this quality becomes essential for design of certain mechanical components such as gears, sliders, dollies or any element metalworking require a high wear resistance.