Abstract
The transformation-induced plasticity (TRIP)-effect is an efficient way to increase the formability in high performance steels. Hence, an optimal stability of the retained austenite is crucial to benefit the most from this effect. In the present work, in-situ high energy X-ray diffraction was used to study the austenite to martensite transformation upon uniaxial tensile loading of a TRIP-assisted steel produced by the quenching and partitioning (Q&P) process. A detailed analysis of the diffraction patterns recorded during deformation allowed to study the austenite stability with respect to the applied partitioning conditions. The austenite stability was found to strongly depend on the applied heat treatment, and could be mainly attributed to the carbon content and to the tempering degree of the surrounding martensitic matrix. Partitioning at 260 °C resulted in a poor austenite stability, while the austenite was almost too stable after partitioning at 360 °C. The optimal combination of strength and ductility was found for partitioning at 400 °C. The micromechanical behavior was analyzed by the evolution of individual lattice strains and the change of full width at half maximum (FWHM). Yielding of austenite could be clearly identified by an increase of FWHM. Martensite showed an unexpected peak narrowing upon yielding. In the case of 2-step Q&P, austenite started to yield after martensite, while yielding occurred almost simultaneously in the case of 1-step Q&P.
Originalsprache | Englisch |
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Aufsatznummer | 101033 |
Seitenumfang | 10 |
Fachzeitschrift | Materialia |
Jahrgang | 15.2021 |
Ausgabenummer | March |
Frühes Online-Datum | 9 Feb. 2021 |
DOIs | |
Publikationsstatus | Veröffentlicht - März 2021 |
Bibliographische Notiz
Funding Information:Funding of the Austrian BMK (846933) in the framework of the program ?Production of the future? and the ?BMK Professorship for Industry? is gratefully acknowledged. We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of the experimental facilities. Parts of this research were carried out at PETRA III and we would like to thank Dr. Nobert Schell for assistance at the P07 high-energy materials science (HEMS) beamline. The research leading to this result has been supported by the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020. In addition, the authors thank Dr. Andreas Landefeld and DI Jan Ingo Platl for the assistance during the HEXRD experiments. Special thanks to Dr. Michael Tkadletz, Dr. Christian Saringer and DI Dominik N?ger for their support regarding data processing.
Funding Information:
Funding of the Austrian BMK (846933) in the framework of the program “Production of the future” and the “BMK Professorship for Industry” is gratefully acknowledged. We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of the experimental facilities. Parts of this research were carried out at PETRA III and we would like to thank Dr. Nobert Schell for assistance at the P07 high-energy materials science (HEMS) beamline. The research leading to this result has been supported by the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020. In addition, the authors thank Dr. Andreas Landefeld and DI Jan Ingo Platl for the assistance during the HEXRD experiments. Special thanks to Dr. Michael Tkadletz, Dr. Christian Saringer and DI Dominik Nöger for their support regarding data processing.
Publisher Copyright:
© 2021