Uncovering the mechanism of dislocation interaction with nanoscale (<4 nm) interphase precipitates in microalloyed ferritic steels
Elena V. Pereloma, David Cortie, Navjeet Singh, Gilberto Casillas, Frank Nießen
Abstract
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}<110> slip–system in the VC nanoparticles.
Topics & Concepts
Materials scienceInterphaseNanopillarShearing (physics)Nanoscopic scaleDislocationTransmission electron microscopyMetallurgyPrecipitationStrengthening mechanisms of materialsScanning electron microscopeNanostructureComposite materialNanotechnologyMicrostructurePhysicsMeteorologyBiologyGeneticsMicrostructure and Mechanical Properties of SteelsMicrostructure and mechanical propertiesHydrogen embrittlement and corrosion behaviors in metals