Searched for: author:"Sietsma, J."
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Marques Pereira, V. (author), Schut, H. (author), Sietsma, J. (author)
An approach to improve the performance of steels for fusion reactors is to reinforce them with oxide nanoparticles. These can hinder dislocation and grain boundary movement and trap radiation-induced defects, thus increasing creep and radiation damage resistance. The present work investigates the thermal stability of the microstructure and...
journal article 2020
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Vittorietti, M. (author), Kok, Piet J.J. (author), Sietsma, J. (author), Li, W. (author), Jongbloed, G. (author)
Modeling microstructures is an interesting problem not just in materials science, but also in mathematics and statistics. The most basic model for steel microstructure is the Poisson-Voronoi diagram. It has mathematically attractive properties and it has been used in the approximation of single-phase steel microstructures. The aim of this...
journal article 2020
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Ou, X. (author), Sietsma, J. (author), Santofimia, Maria Jesus (author)
Molecular dynamics simulations are used to study the effects of tensile loading on nucleation and subsequent growth of bcc phase in pure fcc iron. The results show that orientation variant selection occurs during the stress-induced fcc-to-bcc transformation, which leads to the coalescence of neighbouring bcc platelets with identical...
journal article 2020
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Ravi, A.M. (author), Sietsma, J. (author), Santofimia, Maria Jesus (author)
Low temperature bainite formation in high-carbon steels leads to highly refined microstructures. However, the rate of bainite formation becomes impractically low as the bainite formation temperature decreases. Thus, it is important to create strategies to accelerate the low-temperature bainite formation kinetics in high-carbon steels. In this...
journal article 2020
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Navarro Lopez, A. (author), Hidalgo Garcia, J. (author), Sietsma, J. (author), Santofimia, Maria Jesus (author)
The initial formation of athermal martensite was proven to accelerate the subsequent bainite formation kinetics during isothermal holdings below the martensite-start temperature (M<sub>s</sub>). The presence of prior athermal martensite (PAM) within the phase mixture is expected to modify the overall mechanical response of these newly...
journal article 2020
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Ravi, Ashwath M. (author), Navarro Lopez, A. (author), Sietsma, J. (author), Santofimia, Maria Jesus (author)
Bainite formation in steels typically starts at austenite grain boundaries and continues through nucleation of bainite at newly formed bainitic ferrite/austenite interfaces. Recent experimental evidence has pointed out that austenite to bainite transformation can also proceed in the presence of martensite. Studies suggest that the presence of...
journal article 2020
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Ravi, A.M. (author), Kumar, A. (author), Herbig, Michael (author), Sietsma, J. (author), Santofimia, Maria Jesus (author)
The rate of bainite formation depends on several factors such as austenite grain size, decomposition of austenite into other phases and austenite composition. Although studies have been carried out to understand various factors affecting bainite formation, open lines of investigation still remain. In this work, the effect of ferrite formation...
journal article 2020
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Wempe, Joost (author), van den Brink, Rick (author), Mooldijk, Esmée (author), Feirabend, Nienke (author), Wiersma, R.T. (author), Sietsma, J. (author), Dik, J. (author)
During the Second World War the German occupants of the Netherlands made ample use of the Scheveningen prison near The Hague, popularly nicknamed the Oranjehotel. One former death cell in this infamous prison (Doodencel 601) has been preserved in its original condition, showing wartime inscriptions on the cell walls. Interestingly, a small...
journal article 2020
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Schrama, F.N.H. (author), Ji, Fuzhong (author), Hunt, Adam (author), Beunder, Elisabeth M. (author), Woolf, Rhian (author), Tuling, Alison (author), Warren, Peter (author), Sietsma, J. (author), Boom, R. (author), Yang, Y. (author)
To lower the iron losses of the hot metal desulphurisation (HMD) process, slag modifiers can be added to the slag. Slag modifiers decrease the apparent viscosity of the HMD slag. Most common slag modifiers in industry contain fluoride as a fluidiser. However, fluoride leads to a higher magnesium consumption and has health, safety and...
journal article 2020
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Gavel, D.J. (author), Adema, Allert (author), van der Stel, Jan (author), Peeters, Tim (author), Sietsma, J. (author), Boom, R. (author), Yang, Y. (author)
Physicochemical behaviour of the pellets, sinters and its mixture (60% pellets: 40% sinter) is investigated by a series of smelting and quenching experiments. For all ferrous raw-material beds, three distinct stages of bed shrinkage occur due to indirect reduction, softening and melting. However, the characteristic nature (displacement,...
journal article 2020
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Schrama, F.N.H. (author), Beunder, Elisabeth M. (author), Visser, H. (author), Boom, R. (author), Sietsma, J. (author), Yang, Y. (author)
During the magnesium-lime co-injection process for hot metal desulphurisation, graphite can precipitate as a result of carbon oversaturation. The formed graphite is known to form a layer between the slag and the hot metal. This potentially blocks the sulphides, that are formed during the desulphurisation process, to reach the slag phase thus...
conference paper 2019
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Kumar, A. (author), Saxena, A. K. (author), Kirchlechner, C. (author), Herbig, M. (author), Brinkmann, S. (author), Petrov, R.H. (author), Sietsma, J. (author)
Failure in engineering materials like steels is strongly affected by in-service deleterious alterations in their microstructure. White Etching Layers (WELs) are an example of such in-service alterations in the pearlitic microstructure at the rail surface. Cracks initiate in the rails due to delamination and fracture of these layers and...
journal article 2019
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Ioannidou, C. (author), Arechabaleta Guenechea, Z. (author), Navarro Lopez, A. (author), Rijkenberg, Arjan (author), Dalgliesh, Robert M. (author), Kölling, S. (author), Bliznuk, Vitaliy (author), Pappas, C. (author), Sietsma, J. (author), van Well, A.A. (author), Offerman, S.E. (author)
The precipitation kinetics of vanadium carbides and its interaction with the austenite-to-ferrite phase transformation is studied in two micro-alloyed steels that differ in vanadium and carbon concentrations by a factor of two, but have the same vanadium-to-carbon atomic ratio of 1:1. Dilatometry is used for heat-treating the specimens and...
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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Gavel, D.J. (author), Adema, A.T. (author), van der Stel, Jan (author), Kwakernaak, C. (author), Sietsma, J. (author), Boom, R. (author), Yang, Y. (author)
The melting and dripping behaviour of an iron ore pellet bed mixed with nut coke are investigated through a series of quenching, melting and dripping experiments. In the melting bed of iron ore pellets, nut coke acts as a frame to maintain the passage for the gas flow. The iron carburisation level of the pellet shell is found to control the...
journal article 2019
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Goulas, C. (author), Kumar, A. (author), Mecozzi, M.G. (author), Castro-Cerda, Felipe Manuel (author), Herbig, Michael (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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Kim Lee, B.N. (author), Sietsma, J. (author), Santofimia, 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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Gavel, D.J. (author), Adema, A.T. (author), Stel, Jan Van Der (author), Sietsma, J. (author), Boom, R. (author), Yang, Y. (author)
One of the primary causes that limit the blast furnace productivity is the resistance exerted to the gas flow in the cohesive zone by the ferrous burden. Use of nut coke (10–40 mm) together with ferrous burden proves beneficial for decreasing this resistance. In present study, effect of nut coke addition on the olivine fluxed iron ore pellet...
journal article 2019
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Celada-Casero, Carola (author), Kwakernaak, C. (author), Sietsma, J. (author), Santofimia, 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&amp;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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Chen, Z. (author), Qu, Ying xia (author), Zeilstra, Christiaan (author), Van Der Stel, Jan (author), Sietsma, J. (author), Yang, Y. (author)
HIsarna is a promising ironmaking technology to reduce CO <sub>2</sub> 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
Searched for: author:"Sietsma, J."
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