Fernández, SaraSaraFernándezGarcía García, José OvidioJosé OvidioGarcía GarcíaVerdeja González, Luis FelipeLuis FelipeVerdeja GonzálezVerdeja González, José IgnacioJosé IgnacioVerdeja GonzálezQuintana, María JoséMaría JoséQuintanaGonzalez-Ojeda, RobertoRobertoGonzalez-Ojeda2023-07-312023-07-312013https://scripta.up.edu.mx/handle/20.500.12552/449510.1007/s11668-013-9662-9Certain materials can show superplasticity when traction tested at temperatures higher than 50% of their melting point and with low strain rates ( < 10−2 s−1), showing very high elongations (>100%) without localized necking and mainly intergranular fractures. This behavior requires that the starting grain size is small (<10 μm) so the flow of matter can be non-homogeneous (sliding and rotating of the grain boundaries, accommodated by diffusion). This work presents the superplastic characteristic of shipbuilding steel deformed at 800 °C and a strain rate slower than 10−3 s−1. The fine grain size (5 μm) is obtained when using Nb as a microalloying element and manufactured by controlled rolling processes (three stages). After the superplastic deformation, the steel presents mixed fractures: by decohesion of the hard (pearlite and carbides) and ductile (ferrite) phases and by intergranular sliding of ferrite/ferrite and ferrite/pearlite, just as it happens in stage III of the creep behavior. This is confirmed through the Ashby–Verrall model, according to which the dislocation creep (power-law creep) and diffusion creep (linear-viscous creep) occur simultaneously.Resource Types::text::journal::journal article