Dilatometric Analysis During Tempering of Martensite and Nanostructured Bainite

Abstract

In this work, different techniques were used to perform a comparison study of the tempering behaviour between martensitic and bainitic microstructures developed in two specifically designed bainitic steels with medium C (0.6 wt.%), high Si (>1.5wt%) and V and Mo additions. In order to identify the microstructural evolution, different tempering heat treatments were performed and tracked by dilatometry, at temperatures ranging 450 ºC to 650 ºC during 1h. To complement the dilatometric analysis, a theoretical approach by atomic volumes calculations were performed in an attempt to stablish a correlation between the microstructural changes taking place and the contractions and/or expansions observed