Investigating nano-precipitation in a V-containing HSLA steel using small angle neutron scattering

Abstract

Investigating nano-precipitation in a V-containing {HSLA} steel using small angle neutron scattering. Acta Materialia

A Gibbs Energy Balance Model for Growth Via Diffusional Growth-Ledges

“…The results have been supplemented with recent a posteriori small angle neutron scattering study upon the V-HSLA alloy in question aged varying times from 3 min to 50 hours at 973 K. Taking the results extracted at the shortest aging time to be indicative of the nature of the interphase precipitates formed during the interphase precipitation mechanism (little time for further growth once within the ferritic matrix phase) suggested that the volume fraction of precipitates was in the order of 9 × 10 − 4 . 65) Utilizing the room temperature molar volumes for a stoichiometric VC phase and α respectively from 62) an approximation of the mole fraction of carbon within the interphase precipitates can be approximated using Eq. (19).…”

Quasi in-situ analysis of geometrically necessary dislocation density in α-fibre and γ-fibre during static recrystallization in cold-rolled low-carbon Ti-V bearing microalloyed steel

“…Site-specific FIB lift-outs from recrystallized and un-recrystallized regions were carried out to prepare thin samples with dimension of 6 μm x 6 μm and 0.15 μm to 0.2 μm thickness for TEM precipitate investigation. A modified FIB-lift out method was implemented using initial ion milling at 30 kV by Gallium (Ga) ions followed by ion milling at 500 V at an angle of 12 o on both sides of the FIB-lift out samples to minimise Ga ion damage and re-deposition [51,52]. Thinned samples were attached to a Copper grid and moved to the FEG-TEM FEI Talos F200X operating at 200 kV.…”

“…Thinned samples were attached to a Copper grid and moved to the FEG-TEM FEI Talos F200X operating at 200 kV. Complex precipitates of Titanium-Vanadium carbides (Ti,V)C were identified from high-resolution scanning-transmission electron microscopy (STEM) imaging and chemical maps were obtained using four EDS Super-X Silicon Drift Detectors (SDD) fitted inside the TEM Talos at a collection angle of 0.9 srad [52]. For image analysis, STEM-EDS chemical maps were imported into the ImageJ software [53] for quantitative analysis of precipitates [54].…”

“…For image analysis, STEM-EDS chemical maps were imported into the ImageJ software [53] for quantitative analysis of precipitates [54]. For this quantitative analysis, a minimum of 500 precipitates were analysed from 10 different STEM images taken from two different FIB-lift out samples for each annealing condition [52]. Precipitates were assumed to be circular (in 2D) for quantitative analysis [39,55].…”

Influence of rolling temperature and cooling rate on nano-size carbides in a Ti-Mo microalloyed steel

“…The excellent properties of Ti-Mo microalloyed steels recently became widely recognized, as both a tensile strength of 780 MPa and a hole expansion ratio of 120% were obtained by precipitation strengthening which can reach approximately 300 MPa without reducing the ductility [1]. Numerous studies focused on controlling nanoprecipitation coupling of Ti, Nb, V, and Mo with two or three elements, and many precipitation mechanisms have been proposed to explain these strengthening effects [2][3][4][5][6][7][8]. However, most of these studies concentrated on changes in interphase precipitation characteristics with respect to chemical composition and isothermal phase transformation conditions.…”