Atomic-scale investigation of H-trapping by fine NbC precipitates in a low C ferritic steel

Samanta, S and Gangavarapu, S and Jayabalan, B and Makineni, SK and Dutta, M and Singh, SB (2023) Atomic-scale investigation of H-trapping by fine NbC precipitates in a low C ferritic steel. In: Scripta Materialia, 234 .

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Abstract

The origin of hydrogen trapping by the Nb-carbide precipitates in a ferritic steel was studied at the atomic scale with the help of HRTEM (high resolution transmission electron microscopy) and 3D-APT (atom probe tomography). A Nb-added ferritic steel was prepared in the laboratory and subjected to aging after solutionizing treatment to have fine Nb-carbide precipitates in ferrite matrix. The precipitation kinetics were simulated beforehand using TC-Prisma in Thermocalc software. A large number of nanometer-sized Nb-carbide precipitates were observed in the ferrite matrix using TEM. 3D-APT studies on the steel sample electrolytically charged with D (deuterium) showed that the D atoms are trapped more within the precipitates than at the precipitate-matrix interfaces. It has been argued that H atoms occupy the vacant lattice sites on carbon sub-lattice sites in non-stoichiometric NbC0.83.

Item Type:	Journal Article
Publication:	Scripta Materialia
Publisher:	Acta Materialia Inc
Additional Information:	The copyright for this article belongs to Acta Materialia Inc.
Keywords:	Atoms; Carbides; Ferrite; Niobium alloys; Niobium compounds; Probes, 3d atom probe tomographies; Atomic scale; Carbide precipitate; Ferrite matrix; H-trapping in steel; High-resolution transmission electron microscopy; Hydrogen trapping; Lattice sites; Microalloyed precipitate; Nb carbide, High resolution transmission electron microscopy
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	14 Jun 2023 13:29
Last Modified:	14 Jun 2023 13:29
URI:	https://eprints.iisc.ac.in/id/eprint/81928

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