XRD Analysis of Local Strain Fields in Pearlitic Steels - towards the Fast Examination of Microstructure after Hot Rolling

Abstract

Analysis of the crystallographic anisotropy of the lattice strains, i.e. the analysis of the dependence of the lattice strain on the crystallographic direction, is discussed to be an efficient method for getting information about the mesoscopic local strains and microscopic local strain fields in dual‐phase materials. This technique is illustrated on the example of hot‐rolled pearlitic steels containing ferritic lamellae separated by cementite from each other. In these samples, the information about the local strain fields was further used to build a microstructure model that describes the interaction between crystallites of different phases on the microscopic scale. Such a microstructure model is quite appropriate for examination of the correlations between the structure and properties of the pearlitic steels, because it links the microstructure parameters obtained using X‐ray diffraction on the atomic level with the interaction between the crystallites or grains of different phases, which can more directly be related to the macroscopic mechanical properties of the materials. The second important result of this study was the detection and explanation of several correlations between individual microstructure parameters, which are obtained from X‐ray diffraction. This offers a possibility to use the X‐ray diffraction for a fast microstructure analysis of pearlitic steels, or generally for a fast microstructure analysis of dual‐phase steels, after or even during the rolling processes.

Face Centred Cubic Multi-Component Equiatomic Solid Solutions in the Au-Cu-Ni-Pd-Pt System

“…The features of the type (i) produce an isotropic spread of the line positions and thus an isotropic XRD line broadening; the mean line positions corresponds to the average lattice parameter. The mesoscopic lattice strains cause both, an anisotropic line broadening and an anisotropic change of the lattice parameters [26,27]. The XRD lines are additionally broadened from dislocations that also originate from the preparation of the powders by filing.…”

“…The strain fields can originate either from dislocations or from lattice misfit at the crystallite or grain boundaries. These two effects can be distinguished by employing the effect of the strain on the lattice parameter as shown in [26,27]. The pronounced dependence of the lattice parameters on the crystallographic direction, as shown in Figure 10 indicates that the local lattice strain is produced not only by dislocations but also by a kind of the internal boundaries.…”

Theoretical and experimental study of the antifreeze protein AFP752, trehalose and dimethyl sulfoxide cryoprotection mechanism: correlation with cryopreserved cell viability

“…at a constant temperature. Concerning the size of the ice crystals in frozen solutions, we performed a specimen-to-specimen relative comparison using the diffraction intensity distribution [31,32]. …”

High strain rate behavior, transformation-induced plasticity and fracture toughness characterization of cast and additionally tempered Fe85Cr4Mo8V2C1 alloy manufactured using a rapid solidification technique

“…Lattice parameters and phase fractions were defined from XRD data by applying a Rietveld refinement (MAUD program [38]). The crystallite sizes and the microstrains of strained samples were calculated using a modified Williamson-Hall plot [39]. To determine the distribution of alloying elements, EPMA measurements were carried out using a JEOL JXA-8900RL Electron Probe Micro Analyzer (acceleration voltage 20 kV, beam current 40nA, time per step EPMA line scan 10 s).…”