2020/10/19 by Sung‐Il Baik, Baik, Sung-Il, Ratnesh Kumar Gupta +5
Engineering · Materials Science · #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Metal and Thin Film Mechanics #Microstructure and Mechanical Properties of Steels #Microstructure and mechanical properties
paper · pdf · doi:10.48550/arxiv.2010.09980
openalex publication_date 2020/10/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A 10 wt.% nickel-steel has been developed for high pressures and\nlow-temperature applications, due to its high strength, excellent toughness,\nand low ductile-to-brittle transition temperature (DBTT). Under dynamic loading\nconditions this steel is, however, prone to shear localization that manifests\nas adiabatic shear bands (ASBs). The temperature increases and thermoplastic\nmicrostructural evolution in the ASB are studied in detail, from the\nmacroscopic length scale to the atomic-scale employing correlative\nelectron-backscatter diffraction (EBSD), transmission electron microscopy\n(TEM), and atom-probe tomography (APT). From a calculation of the temperature\nincrease under adiabatic conditions, based on the conversion of plastic-work to\nheat generation, the microstructural transitions in the ASB are discussed\nspecifically for: (i) a b.c.c.-f.c.c. phase-transformation and their elemental\npartitioning; (ii) the thermodynamic model for the compositional change of the\nV(Nb)-rich carbonitride precipitates during a temperature increase; and (iii)\ngrain-refinement and rotation by dynamic/mechanical recrystallization\nprocesses. Solute segregation at subgrain boundaries, measured using the\nGibbsian interfacial excess methodology, reveals how solute segregation\ncontributes to the instability of localized shear-deformation by promoting the\ndepinning of solute elements and the migration of a grain boundary. Finally, a\nkinetic model for grain refinement/rotation within an ASB is described by the\ndynamic recrystallization behavior with: (i) subgrain formation; (ii)\nrotation/refinement by deformation; and (iii) grain growth by subgrain\ncoalescence with further rotation and a temperature increase. The temperature\nincrease under dynamic deformation in an ASB promotes grain boundary migration\nand subgrain coalescence to create a large degree of equiaxed grains with a low\ndensity of imperfections.\n