X-ray evaluation of dislocation density in ODS-Eurofer steel

The evolution with strain of the stored energy in different texture components of cold-rolled IF steel revealed by high resolution X-ray diffraction

“…This approximation is often shown to be consistent with the peak broadening analysis [30,35,36]; (ii) Crystal plasticity is sometimes used to reduce the number of populated systems; this approach is most often shown to improve [11,16,37] or more rarely to deteriorate the quality of the fitting procedure (exposed below) [38]; it is sometimes completed by somewhat arbitrary assumptions on the dislocation character [11]; (iii) All possible slip systems are taken into account and assumed to be equally populated, but the character (screw, edge or mixed) is not a priori set, but deduced from a minimization process [31].…”

“…It is interesting to note that in recent papers relating measurements or calculations of dislocation densities from XRD peaks, e.g. [30][31][32][33], the question of the possible influence of the wall dislocations into the evaluation of the average dislocation density is never addressed. Although -to the authors' knowledge -this fact has never been either proved or inferred, it seems that, in all mentioned cases, it is explicitly assumed that indeed ρ tot = ρ w + ρ c is evaluated in case of symmetrical peaks, whereas ρ c and ρ w are separately evaluated in the case of asymmetrical peaks.…”

In situ characterization of microstructural instabilities: Recovery, recrystallization and abnormal growth in nanoreinforced steel powder

“…In this particular alloy, yttrium, titanium and oxygen are expected to form nanoparticles during hot processing [1,3,4]. Various XRD experiments have shown the benefits of using the synchrotron source to study recrystallization kinetics [18,17]. This study, based on line profile analysis of in situ acquired high-resolution XRD peaks, was performed at the DIFFABS beamline of the synchrotron SOLEIL.…”

“…Since the initial mWH equation developed by Ungàr & Borbély [14], numerous evolutions of this equation have been introduced [15,17,[30][31][32]. In order to compare our results with similar materials, we have chosen to describe the peak broadening by the equation [17]:…”

“…Because of its non-destructive character, X-ray diffraction (XRD) has proved to be an appropriate method for describing dislocation density and crystallite size [14][15][16][17], which are suitable microstructural features for monitoring phenomena such as recovery, recrystallization and grain growth. Nevertheless, the instability and rapid evolution of the ferritic microstructure requires the use of fast and precise in situ characterization methods.…”