scholarly journals Real-Time Investigation of Recovery, Recrystallization and Austenite Transformation during Annealing of a Cold-Rolled Steel Using High Energy X-ray Diffraction (HEXRD)

Metals ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 8 ◽  
Author(s):  
Marc Moreno ◽  
Julien Teixeira ◽  
Guillaume Geandier ◽  
Jean-Christophe Hell ◽  
Frédéric Bonnet ◽  
...  
Keyword(s):  
Annealing Treatment ◽  
High Energy ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Single Experiment ◽  
Austenite Transformation ◽  
X Ray ◽  
Recrystallization Kinetics ◽  
Cold Rolled ◽  
Diffraction Patterns

The annealing process of cold-rolled ferrite/pearlite steel involves numerous metallurgical mechanisms as recovery/recrystallization of deformed phases, ripening of carbide microstructure, and austenite transformation in the intercritical domain. The interactions between these mechanisms govern the morphogenesis of the transformed austenite microstructure and, thus, the final properties of the steel. This paper demonstrates that high energy X-ray diffraction (HEXRD) on synchrotron beamline offers the unique possibility to follow concomitantly these mechanisms in situ during a single experiment. A cold-rolled ferrite-pearlite steel dedicated to the industrial production of Dual-Phase steel serves as case-study. Synchrotron experiments have been conducted in transmission at 100 keV with a 2D detector. Diffraction patterns acquired all along an annealing treatment are first analyzed after circular integration. A Rietveld refinement procedure coupled with a Williamson-Hall approach is used to determine phase transformation and recovery kinetics. In this paper, a new method inspired by the 3D X-ray diffraction tomography is proposed to follow recrystallization kinetics at the same time. It is based on a systematic detection of individual diffraction spots related to newly recrystallized grains appearing on Debye-Scherrer rings. The deduced recrystallization kinetics is compared and validated by more conventional ex situ methods.

PHASE FORMATION AND TEXTURE DEVELOPMENT IN AG-SHEATHED Bi, Pb(2223) TAPES STUDIED BY DIFFERENT IN-SITU AND EX-SITU DIFFRACTION TECHNIQUES

2000 ◽  
Vol 14 (25n27) ◽  
pp. 2688-2693 ◽  
Author(s):  
E. GIANNINI ◽  
E. BELLINGERI ◽  
F. MARTI ◽  
M. DHALLÉ ◽  
V. HONKIMÄKI ◽  
...  
Keyword(s):  
High Energy ◽  
Texture Development ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scattering Geometry ◽  
Reflection Geometry ◽  
Comparison Of The Results ◽  
In Situ Neutron Diffraction

In-situ and ex-situ high energy (80÷88 keV) X-Ray diffraction from a synchrotron radiation source were performed on multifilamentary Bi, Pb(2223)/Ag tapes using a transmission scattering geometry. Several thermo-mechanical procedures were compared, focusing mainly on the texture development of both Bi, Pb(2212) and Bi, Pb(2223) phases. The effect of the periodic pressing on the texture and on the critical current is elucidated. The texture development of the Bi, Pb(2212) phase prior to its transformation into Bi, Pb(2223) was directly observed in-situ at high temperature by using a dedicated high-energy X-ray compatible furnace and a high resolution Image Plate detector. A sharp increase of the Bi, Pb(2212) grain orientation along the [00l] direction was found to occur only above 750°C. Normal state transport measurements are in full agreement with the formation mechanism and with the texture development observed. A comparison of the results with the ones provided by in-situ neutron diffraction and standard low-energy XRD in a reflection geometry is presented.

Development of an in situ synchrotron X-ray total scattering setup under pressurized hydrogen gas

2018 ◽  
Vol 51 (3) ◽  
pp. 796-801 ◽  
Author(s):  
Kouji Sakaki ◽  
Hyunjeong Kim ◽  
Akihiko Machida ◽  
Tetsu Watanuki ◽  
Yoshinori Katayama ◽  
...  
Keyword(s):  
Pair Distribution Function ◽  
Hydrogen Gas ◽  
Ex Situ ◽  
Sample Holder ◽  
Hydrogen Storage Materials ◽  
X Ray Diffraction ◽  
Total Scattering ◽  
X Ray ◽  
Diffraction Patterns

This article describes the development of an in situ gas-loading sample holder for synchrotron X-ray total scattering experiments, particularly for hydrogen storage materials, designed to collect diffraction and pair distribution function (PDF) data under pressurized hydrogen gas. A polyimide capillary with a diameter and thickness of 1.4 and 0.06 mm, respectively, connected with commercially available Swagelok fittings was used as an in situ sample holder. Leakage tests confirmed that this sample holder allows 3 MPa of hydrogen gas pressure and 393 K to be achieved without leakage. Using the developed in situ sample holder, significant background and Bragg peaks from the sample holder were not observed in the X-ray diffraction patterns and their signal-to-noise ratios were sufficiently good. The PDF patterns showed sharp peaks in the r range up to 100 Å. The results of Rietveld and PDF refinements of Ni are consistent with those obtained using a polyimide capillary (1.0 mm diameter and 0.04 mm thickness) that has been used for ex situ experiments. In addition, in situ synchrotron X-ray total scattering experiments under pressurized hydrogen gas up to 1 MPa were successfully demonstrated for LaNi4.6Cu.

Molecular Beam Epitaxial Growth of Nonpolar a-plane InN/ GaN Heterostructures

2012 ◽  
Vol 1396 ◽  
Author(s):  
Mohana K. Rajpalke ◽  
Thirumaleshwara N. Bhat ◽  
Basanta Roul ◽  
Mahesh Kumar ◽  
S. B. Krupanidhi
Keyword(s):  
Schottky Barrier ◽  
Molecular Beam ◽  
Schottky Barrier Height ◽  
High Energy ◽  
Scanning Electron Micrographs ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Beam Epitaxial ◽  
Diffraction Patterns ◽  
Molecular Beam Epitaxial Growth

ABSTRACTNonpolar a-plane InN/GaN heterostructures were grown by plasma assisted molecular beam epitaxy. The growth of nonpolar a- plane InN / GaN heterostructures were confirmed by high resolution x-ray diffraction study. Reflection high energy electron diffraction patterns show the reasonably smooth surface of a-plane GaN and island-like growth for nonpolar a-plane InN film, which is further confirmed by scanning electron micrographs. An absorption edge in the optical spectra has the energy of 0.74 eV, showing blueshifts from the fundamental band gap of 0.7 eV. The rectifying behavior of the I-V curve indicates the existence of Schottky barrier at the InN and GaN interface. The Schottky barrier height (φb) and the ideality factor (η) for the InN/GaN heterostructures found to be 0.58 eV and 2.05 respectively.

Effects of Phosphorus Exposure on Arsenic-Stabilized GaAs 2×4 Surface

1993 ◽  
Vol 312 ◽  
Author(s):  
A. H. Bensaoula ◽  
A. Freundlich ◽  
A. Bensaoula ◽  
V. Rossignol
Keyword(s):  
High Resolution ◽  
Electron Diffraction ◽  
Growth Process ◽  
High Energy ◽  
Ex Situ ◽  
Chemical Beam Epitaxy ◽  
High Energy Electron ◽  
X Ray Diffraction ◽  
X Ray

AbstractPhosphorus exposed GaAs (100) surfaces during a Chemical Beam Epitaxy growth process are studied using in-situ Reflection High Energy Electron Diffraction and ex-situ High Resolution X-ray Diffraction. It is shown that the phosphorus exposure of a GaAs (100) surface in the 500 – 580 °C temperature range results in the formation of one GaP monolayer.

X-Ray Diffraction Patterns in High-Energy Proton Implanted Silicon

1998 ◽  
Vol 168 (1) ◽  
pp. 11-25 ◽  
Author(s):  
K. Wieteska ◽  
W. Wierzchowski ◽  
W. Graeff ◽  
K. D. Dłużewska
Keyword(s):  
High Energy ◽  
X Ray Diffraction ◽  
High Energy Proton ◽  
X Ray ◽  
Energy Proton ◽  
Diffraction Patterns

DSC-TGA Hydrogen Evaluation during Mechanical Milling of AlFe Intermetallic

2013 ◽  
Vol 755 ◽  
pp. 105-110 ◽  
Author(s):  
E. García de León M. ◽  
O. Téllez-Vázquez ◽  
C. Patiño-Carachure ◽  
G. Rosas
Keyword(s):  
Mechanical Milling ◽  
Milling Time ◽  
Hydrogen Generation ◽  
Pure Aluminum ◽  
High Energy ◽  
Milling Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns

Fe40Al60 (at%) intermetallic alloy composition was obtained by conventional casting methods and subsequently subjected to high-energy mechanical milling under different conditions of humidity. All samples were characterized by X-ray diffraction patterns (XRD), transmission electron microcopy (TEM) and DSC-TGA thermogravimetric experiments. After the milling process, the amount of hydrogen generated was determined using thermogravimetric analysis and chemical reactions (stoichiometry). All techniques confirm the formation of bayerite phase which is attributed to the hydrogen embrittlement reaction between the intermetallic material and water to release hydrogen. It was observed that the hydrogen generation is increased as the ball milling time is increased. The quantity of hydrogen evaluated is similar to that obtained in previous reported experiments with pure aluminum and some of its alloys.

Recrystallization Kinetics and Texture Evolution during Annealing of Cold Rolled Fe-Mn-C Alloy

2012 ◽  
Vol 715-716 ◽  
pp. 568-573 ◽  
Author(s):  
Ya Ping Lü ◽  
Dmitri A. Molodov ◽  
Günter Gottstein
Keyword(s):  
Texture Evolution ◽  
Shear Bands ◽  
X Ray Diffraction ◽  
X Ray ◽  
Recrystallization Kinetics ◽  
Nucleation Sites ◽  
Preferential Nucleation ◽  
Cold Rolled ◽  
Mechanical Twins

The recrystallization behavior of 50% cold rolled Fe-22%Mn-0.376%C alloy during annealing at 560°C, 630°C and 700°C was investigated. Microhardness tests were applied for characterization of the recrystallization kinetics, X-ray diffraction and EBSD measurements were utilized to characterize the crystallographic texture and the grain microstructure. The obtained experimental data were evaluated in terms of the JMAK model. The obtained values of the Avrami exponent varied in the range between 0.70 and 1.37. The inhomogeneous grain microstructure after recrystallization is interpreted in terms of non-randomly distributed nuclei. Shear bands, lamellar lines intersecting with mechanical twins and grain boundaries with localized high misorientation gradients were identified to be preferential nucleation sites. No pronounced texture was observed after annealing at 630°C.

Residual stress measurement on the I12 JEEP beamline at Diamond Light Source

2010 ◽  
Vol 1 (SRMS-7) ◽  
Author(s):  
A. M. Korsunsky ◽  
X. Song ◽  
F. Hofmann ◽  
B. Abbey ◽  
M. Xie ◽  
...  
Keyword(s):  
Light Source ◽  
Stress Measurement ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hexagonal Close Packed ◽  
Loading Direction ◽  
Diffraction Patterns ◽  
Set Up ◽  
Energy Dispersive Diffraction

One of the multiple capabilities of the new Joint Engineering, Environmental and Processing (JEEP) beamline I12 at Diamond Light Source is the set-up for polychromatic high-energy X-ray diffraction for the study of polycrystalline deformation and residual stresses. The results and interpretation of the first experiments carried out on JEEP are reported. Energy dispersive diffraction patterns from titanium alloy Ti-6Al-4V were collected using the new 23-cell ‘horseshoe’ detector and interpreted using Pawley refinement to determine the residual elastic strains at the macro- and meso-scale. It provides a clear demonstration of the tensile-compressive hardening asymmetry of the hexagonal close-packed grains oriented with the basal plane perpendicular to the loading direction.

The In Situ Study on the Micro-Structural Characters of IF Steel at Early Stage of Recrystallization Using High-Energy X-Ray

2008 ◽  
Vol 575-578 ◽  
pp. 972-977
Author(s):  
He Tong ◽  
Yan Dong Liu ◽  
Q.W. Jiang ◽  
Y. Ren ◽  
G. Wang ◽  
...  
Keyword(s):  
Annealing Temperature ◽  
Early Stage ◽  
High Energy ◽  
Fiber Texture ◽  
Interstitial Free ◽  
If Steel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cold Rolled

High-energy synchrotron diffraction offers great potential for experimental study of recrystallization kinetics. A fine experimental design to study the recrystallization mechanism of Interstitial Free (IF) steel was implemented in this work. In-situ annealing process of cold-rolled IF steel with 80% reduction was observed using high-energy X-ray diffraction. Results show that, the diffraction intensity of {001}<110> and {112}<110> belong to α-fiber texture component decreased with the annealing temperature increased while {111}<110> did nearly not change and {111}<112> increased; the FMTH decreasing and d-space changing with annealing temperature increasing indicated that the residual stress relaxed completely during recovery.

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