Print Email Facebook Twitter Fundamentals and application of solid-state phase transformations for advanced high strength steels containing metastable retained austenite Title Fundamentals and application of solid-state phase transformations for advanced high strength steels containing metastable retained austenite Author Dai, Zongbiao (Tsinghua University) Chen, Hao (School of Materials Science and Engineering; Tsinghua University) Ding, Ran (Tsinghua University) Lu, Qi (China Science Lab; General Motors) Zhang, Chi (School of Materials Science and Engineering; Tsinghua University) Yang, Zhigang (Tsinghua University) van der Zwaag, S. (TU Delft Novel Aerospace Materials; Tsinghua University) Date 2021 Abstract Over many decades, significant efforts have been made to improve the strength-elongation product of advanced high strength steels (AHSSs) by creating tailored multi-phase microstructures. Successive solid-state phase transformations for steels with a well selected chemical composition turned out to be the key instrument in the realisation of such microstructures. In this contribution, we first provide a brief review of the desired microstructures for Transformation-induced plasticity (TRIP), Carbide-free Bainitic (CFB), Quenching & Partitioning (Q&P) and Medium Manganese steels followed by comprehensive discussions on the phase transformations to be used in their creation. The implications for the steel composition to be selected are addressed too. As the presence of the right amount and type of metastable retained austenite (RA) is of crucial importance for the mechanical performance of these AHSSs, special attention is paid to the important role of successive solid-state phase transformations in creating the desired fraction and composition of RA by suitable element partitioning (in particular C and Mn). This critical partitioning not only takes place during final cooling (austenite decomposition) but also during the back transformation (austenite reversion) during reheating. This review aims to be more than just descriptive of the various findings, but to present them from a coherent thermodynamic / thermo-kinetic perspective, such that it provides the academic and industrial community with a rather complete conceptual and theoretical framework to accelerate the further development of this important class of steels. The detailed stepwise treatment makes the review relevant not only for experts but also metallurgists entering the field. Subject Alloy designAutomotive steelsMicrostructuresRetained austeniteSolid-state phase transformationsSteel chemistry To reference this document use: http://resolver.tudelft.nl/uuid:fb65e570-a5b4-4b3d-90e8-c806fe236f34 DOI https://doi.org/10.1016/j.mser.2020.100590 Embargo date 2021-04-30 ISSN 0927-796X Source Materials Science and Engineering R: Reports, 143 Bibliographical note Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. Part of collection Institutional Repository Document type review Rights © 2021 Zongbiao Dai, Hao Chen, Ran Ding, Qi Lu, Chi Zhang, Zhigang Yang, S. van der Zwaag Files PDF 1_s2.0_S0927796X20300486_main.pdf 21.51 MB Close viewer /islandora/object/uuid:fb65e570-a5b4-4b3d-90e8-c806fe236f34/datastream/OBJ/view