Synchrotron X-ray measurement of residual strain within the nose of a worn manganese steel railway crossing

Dhar, Subash; Zhang, Y; Xu, Ruqing; Danielsen, Hilmar Kjartansson; Jensen, D. Juul

doi:10.1088/1757-899x/219/1/012016

Cited by 10 publications

(5 citation statements)

References 17 publications

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“…Both polychromatic and monochromatic beam modes were used in the present study: a polychromatic beam was used to determine the orientations of the matrix grains around the GNs, and a monochromatic beam was for determining the absolute crystallographic plane spacing, hence the elastic strain. More details about the experimental procedure of the strain measurements are described elsewhere [18,26]. For the present study, absolute lattice plane spacings along directions roughly parallel (maximum 3° off) to the specimen normal direction (ND) were determined for selected matrix grains as illustrated in Fig.…”

Section: Synchrotron Experimentsmentioning

confidence: 99%

Microstructure and residual elastic strain at graphite nodules in ductile cast iron analyzed by synchrotron X-ray microdiffraction

et al. 2019

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The microstructure and residual elastic strain at graphite nodules (GNs) in ductile cast iron produced using either a fast or slow cooling rate have been characterized using synchrotron 3D X-ray Laue microdiffraction. The results show that thermal stress is introduced during cooling and that part of this stress is relaxed by plastic deformation of the polycrystalline ferrite matrix. It is found that the plastic deformation is accommodated by the formation of dislocations and dislocation boundaries, which are organized in a cell structure. The dislocation density quantified based on the microstructure is most pronounced at the GN/matrix interface around small GNs in the fast cooled sample. Residual elastic strain is also present, which is mainly compressive with a maximum of 6.0-9.9 × 10-4 near the GNs. Gradients of plastic deformation and elastic strain field around the GNs are observed. The results document for the first time that both the elastic strain field and the plastic strain field averaged over the grains around the GNs is approximately scaling with GN size and not affected by the cooling rate. The experimental data are compared with simulations by a finite element method, and agreement and disagreement are discussed in detail.

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Section: Synchrotron Experimentsmentioning

confidence: 99%

Microstructure and residual elastic strain at graphite nodules in ductile cast iron analyzed by synchrotron X-ray microdiffraction

et al. 2019

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“…With the third‐generation synchrotron source, the scanning time for a reasonable sized 3D orientation and strain mapping with 3DμXRD is still quite long 51,52 . Upon further deformation, the situation becomes even worse 72 . Additionally, full stress tensor is required in order to obtain a complete picture of the effects of local residual stresses on the mechanical properties.…”

Section: Discussionmentioning

confidence: 99%

Recent trends in X‐ray‐based characterization of nodular cast iron

Andriollo

Zhang

et al. 2020

Mat Design & Process Comms

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Through various examples, this short review presents the main X‐ray‐based techniques that are available to characterize nodular cast iron at the microstructural level. Emphasis is placed on the enormous potential offered by the recent developments in X‐ray tomography, X‐ray diffraction, and digital volume correlation, which allow collecting microstructural and micromechanical information in 4D (3D plus time) during both casting and subsequent mechanical loading. The goal is to demonstrate that for nodular cast iron, which has an inherently three‐dimensional, composite microstructure, X‐ray‐based techniques provide some significant advantages over conventional microscopy. For this reason, these techniques can be instrumental in unveiling the mechanisms controlling both the formation of the microstructure as well as its micromechanical behavior during in‐service loading, thus paving the way to the development of improved process–structure–property relations.

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“…Similarly, 3D strain mapping is also slow, as only one strain component of a selected grain is mapped a time by monochromatic energy scan (see Figures 2 and 3). The situation becomes worse when the sample is further deformed, which leads to an increase in defect density, orientation spread, and strain gradient, which prolongs the exposure time and extends the scanning range of the X-ray energy [64]. Some characterization using electron microscopy and laboratory micro-CT prior to synchrotron experiments are thus usually useful for the site selection and to ensure the success of the beamtime [35,36,38].…”

Section: Discussionmentioning

confidence: 99%

High Resolution Mapping of Orientation and Strain Gradients in Metals by Synchrotron 3D X-ray Laue Microdiffraction

Zhang

Barabash

2019

QuBS

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Synchrotron 3D X-ray Laue microdiffraction, available at beamline 34-ID-E at Advanced Photon Source in Argonne National Laboratory, is a powerful tool for 3D non-destructive mapping of local orientations and strains at sub-micron scale in the bulk. With this technique, it is possible to study local residual stresses developed during manufacturing or while in service due to interactions between, for example, different phases and/or grains with different orientations in materials containing multiple or single phase(s). Such information is essential for understanding mechanical properties and designing advanced materials, but is largely non-existent in the current generation of materials models. In the present paper, the principle and experimental set-up of the 3D microdiffraction are introduced, followed by a description of a method for quantification of the local plastic deformation based on high-angular-resolution orientation maps. The quantification of local residual stresses in two model materials, ductile cast iron (two phases) and partially recrystallized pure nickel (single phase), using 3D microdiffraction will then be presented. The results show that 3D microdiffraction is important for understanding the origin of local residual stresses and to relate them to the microstructural evolution. Finally, the limitations of the 3D microdiffraction on the current generation synchrotron source and new possibilities after the synchrotron upgrade are discussed.

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Synchrotron X-ray measurement of residual strain within the nose of a worn manganese steel railway crossing

Cited by 10 publications

References 17 publications

Microstructure and residual elastic strain at graphite nodules in ductile cast iron analyzed by synchrotron X-ray microdiffraction

Microstructure and residual elastic strain at graphite nodules in ductile cast iron analyzed by synchrotron X-ray microdiffraction

Recent trends in X‐ray‐based characterization of nodular cast iron

High Resolution Mapping of Orientation and Strain Gradients in Metals by Synchrotron 3D X-ray Laue Microdiffraction

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