Abstract
Hot-deformation can refine grain size and change the dynamics of austenite-ferrite phase transformation during thermo-mechanical processing of microalloyed steels. Here, atom probe tomography has been used to characterize nanoscale precipitates and segregation in Ti-Mo microalloyed steels processed with and without hot-deformation at 890°C. It provides a comprehensive understanding of solute redistribution in both the grain interior and grain boundary regions. The results show that coarse (Ti, Mo)C precipitates are formed at grain boundaries, whereas fine precipitates are densely distributed in grain interiors, regardless of deformation conditions. Precipitate-free zones are developed near grain boundaries in the undeformed Ti-Mo steel, but absent in the hot-deformed steel. The elimination of precipitate-free zone in the hot-deformed steel is attributed to the high dislocation density and accelerated γ→α transformation caused by hot-deformation. The majority of Ti, Mo, and C atoms partition into (Ti, Mo)C precipitates, but Mn, Si, and Al atoms are mainly in solute state in ferrite matrix and segregation at grain boundaries. The hot-deformation significantly changes the C segregation at grain boundaries, but has little effect on other solute elements.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
