On the microstructure effects when using electropulsing versus furnace treatments while drawing inox 308L

Abstract

In the present work, microstructure and texture evolution in a commercial 308L stainless steel wire is assessed by comparing several electropulsing configurations and thermal annealing treatments performed during and after a single pass wire drawing process. In this context, the objective is to determine if the electropulsing brings significant differences on the material microstructure with respect to a conventional annealing treatment. To this end, electron backscattered diffraction was used to analyze the microstructure changes in all the studied cases. The results indicate that recrystallization and detwinning are drastically accelerated when in situ electropulsing treatment is applied in the specimen during its drawing. Moreover, electropulsing or large times of furnace treatments after the wire drawing are found to enhance the material conductivity compared to the in situ electropulsing treatment during the wire drawing. Finally, differential scanning calorimetry and material resistivity are performed to analyze the thermal events in a meso/micro scale. Accordingly, the bulk temperature for the electropulsed specimens is assumed to be much higher than the bulk temperature recorded at the surface of the specimen.