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Chen, Z. (author), Qu, Ying xia (author), Zeilstra, Christiaan (author), van der Stel, Jan (author), Sietsma, J. (author), Yang, Y. (author)
emission. Information of phase transformation is essential for reaction analysis of the cyclone reactor of the HIsarna process. In addition, data of density and volume of the ore particles are necessary for estimation of the residence time of the particles in the cyclone...
journal article 2019
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Alonso de Celada Casero, Carola (author), Kwakernaak, C. (author), Sietsma, J. (author), Santofimia Navarro, Maria Jesus (author)
The influence of the prior austenite grain size (PAGS), varying between 6 and 185 μm, on the microstructural development of a low carbon steel during quenching and partitioning (Q&P) processing is investigated. The effect on the size and morphological aspects of the microconstituents is discussed based on the kinetics of carbon...
journal article 2019
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Alonso de Celada Casero, Carola (author), Sietsma, J. (author), Santofimia Navarro, Maria Jesus (author)
There is sufficient experimental evidence to propose that the formation kinetics of athermal martensite directly depends on the austenite grain structure from which the martensite forms. Yet, this dependence is frequently ignored. The present study investigates the role of the prior austenite grain size (PAGS) in the martensitic...
journal article 2019
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Vittorietti, M. (author), Kok, Piet J.J. (author), Sietsma, J. (author), Jongbloed, G. (author)
Understanding the intricate and complex materials microstructure and how it is related to materials properties is an important problem in the Materials Science field. For a full comprehension of this relation, it is fundamental to be able to describe the main characteristics of the 3-dimensional microstructure. The most basic model used for...
journal article 2019
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Karewar, S.V. (author), Sietsma, J. (author), Santofimia Navarro, Maria Jesus (author)
Molecular dynamics simulations are used to investigate the atomic effects of carbon (C) addition in Fe on the martensitic phase transformation in the presence of pre-existing defects such as stacking faults and twin boundaries. The pre-existing defect structures in Fe-C alloys have the same effect on the atomistic mechanisms of martensitic...
journal article 2019
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Kumar, A. (author), Agarwal, G. (author), Petrov, R.H. (author), Goto, S. (author), Sietsma, J. (author), Herbig, M (author)
The formation of White (WEL) and Brown Etching Layers (BEL) on rail raceways during service causes the initiation of microcracks which finally leads to failure. Detailed characterization of the WEL and the BEL in a pearlitic rail steel is carried out from micrometer to atomic scale to understand their microstructural evolution. A...
journal article 2019
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Kim Lee, B.N. (author), Sietsma, J. (author), Santofimia Navarro, Maria Jesus (author)
Carbon redistribution is known to occur during room temperature aging of Fe-C martensite. One of the proposed mechanisms in the literature by which carbon redistributes is spinodal decomposition, a thermodynamically driven reaction in which the alloy undergoes separation into carbon-rich and carbon-poor regions, giving rise to modulations in...
journal article 2019
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Goulas, C. (author), Kumar, A. (author), Mecozzi, M.G. (author), Castro Cerda, Felipe Manuel (author), Herbig, M (author), Petrov, R.H. (author), Sietsma, J. (author)
Atomic-scale investigation was performed on 51CrV4 steel, isothermally held at different temperatures within the bainitic temperature range. Transmission electron microscopy (TEM) analysis revealed three different morphologies: lower, upper, and inverse bainite. Atom Probe Tomography (APT) analysis of lower bainite revealed cementite...
journal article 2019
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Alizadeh Otorabad, H. (author), Tehrani, Parisa Hosseini (author), Younesian, Davood (author), Sietsma, J. (author), Petrov, R.H. (author)
Studying the temperature evolution of the thermally affected zone (TAZ) of sliding surfaces is crucial because of its influence on microstructural evolution, wear, and fatigue. Due to the complexity of thermal analysis of sliding bodies, relationships that predict their surface temperature evolution are very helpful because they can be used as...
journal article 2018
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Nishikawa, A.S. (author), Santofimia Navarro, M.J. (author), Sietsma, J. (author), Goldenstein, Hélio (author)
In the present study the microstructural evolution and kinetics of carbon redistribution during the partitioning step of the Quenching and Partitioning process are investigated by means of a modeling approach that simultaneously considers the martensite-austenite carbon partitioning and the decomposition of austenite into bainitic ferrite....
journal article 2018
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Venkatesan, P. (author), Vander Hoogerstraete, Tom (author), Hennebel, Tom (author), Binnemans, Koen (author), Sietsma, J. (author), Yang, Y. (author)
NdFeB magnet waste is one of the important secondary resources from which rare-earth elements (REEs) can be recovered. Herein we present an electrochemical route to selectively extract REEs from the magnet waste at room temperature. First, the magnet waste was partially leached with HCl. The partial leachate along with undissolved magnet...
journal article 2018
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Navarro Lopez, A. (author), Hidalgo Garcia, J. (author), Sietsma, J. (author), Santofimia Navarro, M.J. (author)
The accelerated formation of bainite in presence of martensite is opening a new processing window for the steel industry. However, for a feasible industrial implementation, it is necessary to determine the mechanical behaviour of the steels developed under such conditions. This study focuses on analysing the effects of the formation of...
journal article 2018
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Gavel, D.J. (author), Song, Qingshi (author), Adema, A.T. (author), van der Stel, Jan (author), Sietsma, J. (author), Boom, R. (author), Yang, Y. (author)
In the blast furnace, nut coke is utilized in a mixture with the ferrous burden to improve the gas permeability. Although applied in a broad range (10–40 mm, 2–23 wt-%), limited information is available on changed burden behaviour in its presence. In the present study, the detailed characterization was performed on the iron ore pellets quenched...
journal article 2018
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Chen, Z. (author), Qu, Yingxia (author), Zeilstra, Christiaan (author), van der Stel, Jan (author), Sietsma, J. (author), Yang, Y. (author)
Melting and reduction of fine iron ore particles in the gas environment of a HIsarna smelting cyclone is a critically important topic, but very limited information is currently available except for some experimental data from high temperature drop tube furnace (HTDF). This work discusses the equilibrium state of reacting iron ore in the HTDF...
journal article 2018
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Arechabaleta Guenechea, Z. (author), van Liempt, P. (author), Sietsma, J. (author)
Understanding the intricate structure of dislocations in metals is a major issue in materials science. In this paper we present a comprehensive approach for the characterisation of dislocation networks, resulting in accurate quantification and significantly increasing the insight into the dislocation structure. Dislocation networks in metals...
journal article 2018
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Karewar, S.V. (author), Sietsma, J. (author), Santofimia Navarro, M.J. (author)
Molecular dynamics (MD) simulations are used to study the effect of different defect configurations and their arrangements in the parent fcc phase on atomistic mechanisms during the martensitic transformation mechanisms in pure Fe. The defect configurations considered are stacking faults (SF) and twin boundaries (TB) in single crystal fcc. Three...
journal article 2018
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Peelman, S. (author), Kooijman, D. (author), Sietsma, J. (author), Yang, Y. (author)
The present study proposes three distinct processes to recycle rare earth elements (REE) from two low-grade secondary resources: REE-containing mine tailings and ferrous scrap from shredded waste of electrical and electronic equipment (WEEE). The first developed process extracts both REE and phosphorus from the apatite mineral contained within...
journal article 2018
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Venkatesan, P. (author), Sun, Z.H.I. (author), Sietsma, J. (author), Yang, Y. (author)
In this manuscript, we demonstrate a room temperature electrochemical process for efficiently recycling NdFeB magnet waste. First, the magnet waste was completely leached with HCl and then, in-situ electrochemical oxidation was performed to selectively oxidize Fe(II) in the leachate to Fe(III). Finally, oxalic acid was added directly to the...
journal article 2018
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Peelman, S. (author), Sietsma, J. (author), Yang, Y. (author)
Neodymium is a critical element used in many high-tech applications. However, despite this, the EU is entirely dependent on China for its Nd supply. This has driven the EU to develop recycling strategies to recover its Nd from end-of-life (EoL) products and wastes, and establish a domestic supply. This paper proposes a process to recycle Nd from...
journal article 2018
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Wu, J. (author), Petrov, R.H. (author), Kölling, S. (author), Godet, S (author), Sietsma, J. (author)
Micro- to nano-scale characterization of the microstructures in the white etching layer (WEL), observed in a Dutch R260 Mn grade rail steel, was performed via various techniques. Retained austenite in the WEL was identified via electron backscatter diffraction (EBSD), automatic crystallographic orientation mapping in transmission electron...
journal article 2018
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