Resumen de Eff ect of the pl astic strain on the bainitic transformation during ausforming treatments
Adriana Eres Castellanos, Francisca G. Caballero, Carlos García Mateo
The so-called ausforming thermomechanical treatment consists in plastically deforming a fully austenitized steel prior to either a martensitic or a bainitic transformation. This treatment could be an alternative to obtain nanostructured bainite in medium carbon steels. However, before this alternative is implemented, it is important to study the effect of the plastic deformation on the transformation, especially when steels are deformed at medium or low temperatures, i.e. temperatures lying in the hiatus between the ferrite/pearlite and the bainite regions or lower temperatures, respectively. In this paper, the effect of the plastic deformation at medium temperatures on bainitic ferrite plate thickness, volume fraction and hardness has been studied in a medium carbon steel (0.4 mass con-tent in %) by means of high-resolution dilatometry, scanning electron microscopy and X-Ray diffraction. To do so, microstructures obtained after ausforming at 520ºC (epsilon = 10% and 30%) have been compared to the microstructure obtained by a pure isothermal treatment (epsilon = 0%) at 325ºC, see Figure 1a.
