scholarly journals ’Quenching and Partitioning’ - An In Situ Approach to Characterize the Process Kinetics and the Final Microstructure of TRIP-Assisted Steel

2011 ◽  
Vol 409 ◽  
pp. 713-718 ◽  
Author(s):  
Thomas Rieger ◽  
Klaus Herrmann ◽  
Dagmar Carmele ◽  
Stephan Meyer ◽  
Thomas Lippmann ◽  
...  

The ‘Quenching and Partitioning’ (Q&P) concept aims to increase the strength level of conventional TRIP-assisted advanced high strength steel (AHSS) by replacing ferritic constituents by tempered martensite. The Q&P heat treatment process involves austenitization and interrupted quenching followed by carbon partitioning from martensite to austenite at elevated temperatures. The final microstructure is traditionally investigated at room temperature after metallographic preparation by microscopy and x-ray analysis with laboratory tubes. Besides other disadvantages the established characterization methods are not adequate to observe the development of the microstructure during Q&P treatment. In the present work the microstructural evolution during Q&P processing was monitored by in-situ diffraction experiments using very hard (100 keV) synchrotron x-ray radiation. Debye-Scherrer rings were recorded as a function of time and temperature during the heat treatment in a state-of-the-art dilatometer (type Bähr DIL805AD) at the Engineering Materials Science beamline HARWI-II (HZG outstation at Deutsches Elektronensynchrotron (DESY), Hamburg). The diffraction patterns contain quantitative information on the phases present in the sample (for more details cf. Abstract Carmele et al, this conference). The evolution of the austenite phase fraction during the partitioning treatment at the quench temperature (1-step Q&P) is discussed exemplarily for a Si-based TRIP steel with additions of Ni.

2011 ◽  
Vol 409 ◽  
pp. 660-665 ◽  
Author(s):  
Dagmar Carmele ◽  
Thomas Rieger ◽  
Klaus Herrmann ◽  
Stephan Meyer ◽  
Thomas Lippmann ◽  
...  

Innovative steel materials of the third generation of advanced high-strength steel (AHSS) are based on complex multiphase microstructures on a submicron scale, which are adjusted in a heat treatment procedure. Established methods for microstructural characterization are usually applied after the heat treatment process (ex-situ) at room temperature and comprise amongst others X-ray analysis based on laboratory tubes with photon energies of several keV. The corresponding penetration depths are on the micron scale. Additionally, the results may be affected by the metallographic preparation process. Using very hard synchrotron X-ray radiation with photon energies of up to 100 keV, penetration depths in the millimetre range are realized and macroscopic volumes (mm³) can be investigated. Furthermore the photon flux of synchrotron sources is several orders of magnitude higher compared to laboratory tubes. Consequently in-situ measurements during a heat treatment process can be performed. Using the example of the standardized multiphase TRIP steel HCT690T, a microstructural investigation with high energy synchrotron X-ray radiation is discussed and compared to established diffraction methods using Co-and Cu-Kα-radiation. In-situ diffraction measurements during a heat treatment are exemplarily shown.


2021 ◽  
Vol 7 (3) ◽  
pp. eabc8660
Author(s):  
F. Mirani ◽  
A. Maffini ◽  
F. Casamichiela ◽  
A. Pazzaglia ◽  
A. Formenti ◽  
...  

Among the existing elemental characterization techniques, particle-induced x-ray emission (PIXE) and energy-dispersive x-ray (EDX) spectroscopy are two of the most widely used in different scientific and technological fields. Here, we present the first quantitative laser-driven PIXE and laser-driven EDX experimental investigation performed at the Centro de Láseres Pulsados in Salamanca. Thanks to their potential for compactness and portability, laser-driven particle sources are very appealing for materials science applications, especially for materials analysis techniques. We demonstrate the possibility to exploit the x-ray signal produced by the co-irradiation with both electrons and protons to identify the elements in the sample. We show that, using the proton beam only, we can successfully obtain quantitative information about the sample structure through laser-driven PIXE analysis. These results pave the way toward the development of a compact and multifunctional apparatus for the elemental analysis of materials based on a laser-driven particle source.


MRS Advances ◽  
2018 ◽  
Vol 3 (11) ◽  
pp. 563-567 ◽  
Author(s):  
Quentin Altemose ◽  
Katrina Raichle ◽  
Brittani Schnable ◽  
Casey Schwarz ◽  
Myungkoo Kang ◽  
...  

ABSTRACTTransparent optical ZnO–Bi2O3–B2O3 (ZBB) glass-ceramics were created by the melt quenching technique. In this work, a melt of the glass containing stoichiometric ratios of Zn/Bi/B and As was studied. Differential scanning calorimeter (DSC) measurements was used to measure the thermal behavior. VIS/NIR transmission measurements were used to determine the transmission window. X-ray diffraction (XRD) was used to determine crystal phase. In this study, we explore new techniques and report a detailed study of in-situ XRD of the ZBB composition in order to correlate nucleation temperature, heat treatment temperature, and heat treatment duration with induced crystal phase.


2021 ◽  
Vol 92 (3) ◽  
pp. 033704
Author(s):  
Rongqi Zhu ◽  
Zhaoliang Qu ◽  
Shuo Yang ◽  
Daining Fang
Keyword(s):  

1999 ◽  
Vol 556 ◽  
Author(s):  
P. E. Raison ◽  
R. G. Haire ◽  
T. Sato ◽  
T. Ogawa

AbstractPolycrystalline pyrochlore oxides consisting of selected f elements (lanthanides and actinides) and Zr and Hf have been prepared and characterized. Characterization to date has been primarily by X-ray diffraction, both at room and at elevated temperatures. Initial studies concentrated on selected lanthanides and the Np, Pu and Am analogs (reported here) but have been extended to the other actinide elements through Cf. Data from these studies have been used to establish a systematic correlation regarding the fundamental materials science of these particular pyrochlores and structurally related fluorite-type dioxides. In addition to pursuing their materials science, we have addressed some potential technological applications for these materials. Some of the latter concern: (1) immobilization matrices; (2) materials for transmutation concepts; and (3) special nuclear fuel forms that can minimize the generation of nuclear wastes. For f elements that display both a III and IV oxidation state in oxide matrices, the synthetic path required for producing the desired pyrochlore oxide is dictated by their pseudo-oxidation potential the stability of the compound towards oxygen uptake. For the f elements that display an oxidationreduction cycle for pyrochlore-dioxide solid solution, X-ray diffraction can be used to identify the composition in the oxidation-reduction cycle, the oxygen stoichiometry and/or the composition. This paper concentrates on the Np, Pu and Am systems, and addresses the above aspects, the role of the crystal matrix in controlling the ceramic products as well as discussingsome custom-tailored materials.


2020 ◽  
Vol 53 (4) ◽  
pp. 1163-1166
Author(s):  
Karsten Mesecke ◽  
Winfried Malorny ◽  
Laurence N. Warr

This note describes an autoclave chamber developed and constructed by Anton Paar and its application for in situ experiments under hydrothermal conditions. Reactions of crystalline phases can be studied by successive in situ measurements on a conventional laboratory X-ray diffractometer with Bragg–Brentano geometry at temperatures <483 K and saturated vapour pressure <2 MPa. Variations in the intensity of X-ray diffraction reflections of both reactants and products provide quantitative information for studying the reaction kinetics of both dissolution and crystal growth. Feasibility is demonstrated by studying a cementitious mixture used for autoclaved aerated concrete production. During a period of 5.7 h at 466 K and 1.35 MPa, the crystallization of torbermorite and the partial consumption of quartz were monitored.


2021 ◽  
Vol 54 (3) ◽  
Author(s):  
Semën Gorfman ◽  
David Spirito ◽  
Netanela Cohen ◽  
Peter Siffalovic ◽  
Peter Nadazdy ◽  
...  

Laboratory X-ray diffractometers play a crucial role in X-ray crystallography and materials science. Such instruments still vastly outnumber synchrotron facilities and are responsible for most of the X-ray characterization of materials around the world. The efforts to enhance the design and performance of in-house X-ray diffraction instruments benefit a broad research community. Here, the realization of a custom-built multipurpose four-circle diffractometer in the laboratory for X-ray crystallography of functional materials at Tel Aviv University, Israel, is reported. The instrument is equipped with a microfocus Cu-based X-ray source, collimating X-ray optics, four-bounce monochromator, four-circle goniometer, large (PILATUS3 R 1M) pixel area detector, analyser crystal and scintillating counter. It is suitable for a broad range of tasks in X-ray crystallography/structure analysis and materials science. All the relevant X-ray beam parameters (total flux, flux density, beam divergence, monochromaticity) are reported and several applications such as determination of the crystal orientation matrix and high-resolution reciprocal-space mapping are demonstrated. The diffractometer is suitable for measuring X-ray diffraction in situ under an external electric field, as demonstrated by the measurement of electric-field-dependent rocking curves of a quartz single crystal. The diffractometer can be used as an independent research instrument, but also as a training platform and for preparation for synchrotron experiments.


2016 ◽  
Vol 49 (2) ◽  
pp. 700-704 ◽  
Author(s):  
Paul A. Shade ◽  
David B. Menasche ◽  
Joel V. Bernier ◽  
Peter Kenesei ◽  
Jun-Sang Park ◽  
...  

An evolving suite of X-ray characterization methods are presently available to the materials community, providing a great opportunity to gain new insight into material behavior and provide critical validation data for materials models. Two critical and related issues are sample repositioning during an in situ experiment and registration of multiple data sets after the experiment. To address these issues, a method is described which utilizes a focused ion-beam scanning electron microscope equipped with a micromanipulator to apply gold fiducial markers to samples for X-ray measurements. The method is demonstrated with a synchrotron X-ray experiment involving in situ loading of a titanium alloy tensile specimen.


2018 ◽  
Vol 284 ◽  
pp. 351-356 ◽  
Author(s):  
Mikhail V. Maisuradze ◽  
Maksim A. Ryzhkov

The high strength aerospace steel alloyed with Cr, Mn, Si, Ni, W and Mo was studied. The austenite transformations under continuous cooling conditions were investigated using the dilatometer analysis at the cooling rates 0.1...30 °C/s. The mechanical properties of the studied steel were determined after the conventional quenching and tempering heat treatment. The dependences of the mechanical properties on the tempering temperature were obtained. The novel quenching and partitioning heat treatment was applied to the steel under consideration. The microstructure and the mechanical properties were studied after three different modes of the quenching and partitioning (QP) treatment: single-stage QP, two-stage QP and single-stage QP with subsequent tempering (QPT).


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