Use of Space-Resolved in-Situ High Energy X-ray Diffraction for the Characterization of the Compositional Dependence of the Austenite-to-Ferrite Transformation Kinetics in Steels

In-situ high energy X-Ray diffraction (HEXRD) was used on compositionally graded steels to study the effect of substitutional elements on ferrite growth kinetics in Fe–C–X and Fe–C–X–Y systems. Two systems were selected to illustrate the applicability of the combinatorial approach in studying such transformations, Fe–C–Mn and Fe–C–Mn–Mo. Comparison between the measured ferrite growth kinetics using HEXRD and the predicted ones using Para-Equilibrium (PE) and Local Equilibrium with Negligible Partitioning (LENP) models indicates that the fractions reached at the stasis of transformation are lower than the predicted ones. Experiments indicated a deviation of measured kinetics from both PE and LENP models when increasing Mn and decreasing Mo (in Fe–C–Mn–Mo system). The large amount of data that can be obtained using this approach can be used for validating existing models describing ferrite growth kinetics.

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In-situ characterization of solidification and microstructural evolution during interrupted thermal fatigue in SAC305 and SAC105 solder joints using high energy X-ray diffraction and post-mortem EBSD analysis

Materials Science and Engineering A ◽

10.1016/j.msea.2020.140584 ◽

2021 ◽

Vol 802 ◽

pp. 140584

Author(s):

Quan Zhou ◽

Tae-Kyu Lee ◽

Thomas R. Bieler

Keyword(s):

Microstructural Evolution ◽

Thermal Fatigue ◽

High Energy ◽

Post Mortem ◽

X Ray Diffraction ◽

In Situ Characterization ◽

X Ray ◽

Sac105 Solder

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In situ characterization of residual stress evolution during heat treatment of SiC/SiC ceramic matrix composites using high‐energy X‐ray diffraction

Journal of the American Ceramic Society ◽

10.1111/jace.17493 ◽

2020 ◽

Vol 104 (3) ◽

pp. 1424-1435

Author(s):

Michael W. Knauf ◽

Craig P. Przybyla ◽

Paul A. Shade ◽

Jun‐Sang Park ◽

Andrew J. Ritchey ◽

...

Keyword(s):

Ceramic Matrix Composites ◽

High Energy ◽

Matrix Composites ◽

Stress Evolution ◽

X Ray Diffraction ◽

In Situ Characterization ◽

X Ray ◽

Sic Ceramic

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In situ characterization of Grade 92 steel during tensile deformation using concurrent high energy X-ray diffraction and small angle X-ray scattering

Journal of Nuclear Materials ◽

10.1016/j.jnucmat.2013.04.063 ◽

2013 ◽

Vol 440 (1-3) ◽

pp. 81-90 ◽

Cited By ~ 28

Author(s):

Leyun Wang ◽

Meimei Li ◽

Jonathan Almer

Keyword(s):

Small Angle ◽

Tensile Deformation ◽

High Energy ◽

X Ray Diffraction ◽

In Situ Characterization ◽

X Ray ◽

X Ray Scattering ◽

Grade 92 Steel

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In Situ High Energy X-ray Diffraction Characterization of Phase Transformations and Mechanical Behaviors in Rapidly Solidified Titanium and Stainless Steel Alloys

10.2172/1756790 ◽

2021 ◽

Author(s):

Nathan Johnson

Keyword(s):

Stainless Steel ◽

Phase Transformations ◽

High Energy ◽

Mechanical Behaviors ◽

X Ray Diffraction ◽

Steel Alloys ◽

X Ray ◽

Rapidly Solidified

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In Situ Analysis of the Phase Transformation Kinetics in the β-Water-Quenched Ti-5Al-5Mo-5V-3Cr-1Zr Alloy during Ageing after Fast Heating

Quantum Beam Science ◽

10.3390/qubs4010012 ◽

2020 ◽

Vol 4 (1) ◽

pp. 12

Author(s):

Rafael Paiotti Marcondes Guimarães ◽

Bruna Callegari ◽

Fernando Warchomicka ◽

Katherine Aristizabal ◽

Flavio Soldera ◽

...

Keyword(s):

Phase Transformation ◽

High Energy ◽

Transformation Kinetics ◽

X Ray Diffraction ◽

Fast Heating ◽

X Ray ◽

Β Phase ◽

Phase Transformation Kinetics ◽

Structural Applications

Thermal treatments are the main route to achieve improvements in mechanical properties of β-metastable titanium alloys developed for structural applications in automotive and aerospace industries. Therefore, it is of vital importance to determine phase transformation kinetics and mechanisms of nucleation and precipitation during heat treatment of these alloys. In this context, the present paper focuses on the assessment of solid-state transformations in a β-water-quenched Ti-5Al-5Mo-5V-3Cr-1Zr alloy during the early stages of ageing treatment at 500 °C. In situ tracking of transformations was performed using high-energy synchrotron X-ray diffraction. The transformation sequence β + ω → α + α”iso + β is proposed to take place during this stage. Results show that isothermal α” phase precipitates from ω and from spinodal decomposition domains of the β phase, whereas α nucleates from ω, β and also from α” with different morphologies. Isothermal α” is considered to be the regulator of transformation kinetics. Hardness measurements confirm the presence of ω, although this phase was not detected by X-ray diffraction during the in situ treatment.

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The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071107 ◽

1973 ◽

Vol 31 ◽

pp. 132-133 ◽

Cited By ~ 1

Author(s):

R. E. Herfert

Keyword(s):

Surface Characterization ◽

Analytical Techniques ◽

X Ray Diffraction ◽

Depth Of Penetration ◽

X Ray ◽

The Past ◽

Transmission Electron ◽

Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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In-Situ High-Energy X-ray Diffraction Study of Austenite Decomposition During Rapid Cooling and Isothermal Holding in Two HSLA Steels

Metallurgical and Materials Transactions A ◽

10.1007/s11661-021-06192-x ◽

2021 ◽

Vol 52 (5) ◽

pp. 1812-1825

Author(s):

Sen Lin ◽

Ulrika Borggren ◽

Andreas Stark ◽

Annika Borgenstam ◽

Wangzhong Mu ◽

...

Keyword(s):

Isothermal Holding ◽

Weight Percent ◽

High Energy ◽

Decomposition Kinetics ◽

Bainitic Transformation ◽

Austenite Decomposition ◽

X Ray Diffraction ◽

Rapid Cooling ◽

X Ray

AbstractIn-situ high-energy X-ray diffraction experiments with high temporal resolution during rapid cooling (280 °C s−1) and isothermal heat treatments (at 450 °C, 500 °C, and 550 °C for 30 minutes) were performed to study austenite decomposition in two commercial high-strength low-alloy steels. The rapid phase transformations occurring in these types of steels are investigated for the first time in-situ, aiding a detailed analysis of the austenite decomposition kinetics. For the low hardenability steel with main composition Fe-0.08C-1.7Mn-0.403Si-0.303Cr in weight percent, austenite decomposition to polygonal ferrite and bainite occurs already during the initial cooling. However, for the high hardenability steel with main composition Fe-0.08C-1.79Mn-0.182Si-0.757Cr-0.094Mo in weight percent, the austenite decomposition kinetics is retarded, chiefly by the Mo addition, and therefore mainly bainitic transformation occurs during isothermal holding; the bainitic transformation rate at the isothermal holding is clearly enhanced by lowered temperature from 550 °C to 500 °C and 450 °C. During prolonged isothermal holding, carbide formation leads to decreased austenite carbon content and promotes continued bainitic ferrite formation. Moreover, at prolonged isothermal holding at higher temperatures some degenerate pearlite form.

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