Print Email Facebook Twitter Evolution of the precipitate composition during annealing of vanadium micro-alloyed steels by in-situ SANS Title Evolution of the precipitate composition during annealing of vanadium micro-alloyed steels by in-situ SANS Author Ioannidou, C. (TU Delft (OLD) MSE-1) Navarro Lopez, A. (TU Delft (OLD) MSE-3) Rijkenberg, Arjan (Tata Steel) Dalgliesh, Robert M. (STFC) Koelling, Sebastian (Eindhoven University of Technology) Pappas, C. (TU Delft RST/Neutron and Positron Methods in Materials) Sietsma, J. (TU Delft Materials Science and Engineering; TU Delft (OLD) MSE-3) van Well, A.A. (TU Delft RID/Algemeen/Bedrijfsondersteuning) Offerman, S.E. (TU Delft (OLD) MSE-1) Department Materials Science and Engineering Date 2020 Abstract In-situ Small-Angle Neutron Scattering (SANS) is used to determine the time evolution of the chemical composition of precipitates at 650 °C and 700 °C in three micro-alloyed steels with different vanadium (V) and carbon (C) concentrations. Precipitates with a distribution of substoichiometric carbon-to-metal ratios are measured in all steels. The precipitates are initially metastable with a high iron (Fe) content, which is gradually being substituted by vanadium during isothermal annealing. Eventually a plateau in the composition of the precipitate phase is reached. Faster changes in the precipitate chemical composition are observed at the higher temperature in all steels because of the faster vanadium diffusion at 700 °C. At both temperatures, the addition of more vanadium and more carbon to the steel has an accelerating effect on the evolution of the precipitate composition as a result of a higher driving force for precipitation. Addition of vanadium to the nominal composition of the steel leads to more vanadium rich precipitates, with less iron and a smaller carbon-to-metal ratio. Atom Probe Tomography (APT) shows the presence of precipitates with a distribution of carbon-to-metal ratios, ranging from 0.75 to 1, after 10 h of annealing at 650 °C or 700 °C in all steels. These experimental results are coupled to ThermoCalc equilibrium calculations and literature findings to support the Small-Angle Neutron Scattering results. Subject Atom Probe Tomographychemical composition evolutionin-situ Small-Angle Neutron Scatteringvanadium carbidesvanadium micro-alloyed steels To reference this document use: http://resolver.tudelft.nl/uuid:61f0b17c-ac9a-4853-baf1-fc317e945504 DOI https://doi.org/10.1016/j.actamat.2020.09.083 ISSN 1359-6454 Source Acta Materialia, 201, 217-230 Part of collection Institutional Repository Document type journal article Rights © 2020 C. Ioannidou, A. Navarro Lopez, Arjan Rijkenberg, Robert M. Dalgliesh, Sebastian Koelling, C. Pappas, J. Sietsma, A.A. van Well, S.E. Offerman Files PDF 1_s2.0_S1359645420307862_main.pdf 3.03 MB Close viewer /islandora/object/uuid:61f0b17c-ac9a-4853-baf1-fc317e945504/datastream/OBJ/view