Uncovering the mechanism of dislocation interaction with nanoscale (<4 nm) interphase precipitates in microalloyed ferritic steels

Authors

Elena V. Pereloma, University of WollongongFollow
David L. Cortie, University of WollongongFollow
Navjeet Singh, University of WollongongFollow
Gilberto Casillas, University of Wollongong
Frank Niessen, University of WollongongFollow

RIS ID

143363

Publication Details

Pereloma, E., Cortie, D., Singh, N., Casillas-Garcia, G. & Niessen, F. (2020). Uncovering the mechanism of dislocation interaction with nanoscale (<4 >nm) interphase precipitates in microalloyed ferritic steels. Materials Research Letters, 8 (9), 341-347.

Abstract

© 2020, © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. Nanoscale interphase precipitation in microalloyed ferritic steels provides a remarkable (200–400 MPa) strengthening increment, however its origin is unclear. Scanning transmission electron microscopy revealed step formation at the matrix/precipitate interface after both macroscopic uniaxial tension and nanopillar compression testing. Supported by Density Functional Theory modelling, dislocation shearing of nano-sized (<4 >nm) VC precipitates was identified as a strengthening mechanism. The findings suggest the operation of an unusual {001} slip–system in the VC nanoparticles. IMPACT STATEMENT: Shearing of VC nanoparticles by dislocations on a non-traditional slip–system was identified as a strengthening mechanism for steels with nanoparticles.