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Skowronek, Adam (author), Grajcar, Adam (author), Petrov, R.H. (author)Depending on the alloy composition, intercritical annealing may provide different phases in the microstructure. For low-alloyed dual-phase (DP) steels it is usually ferrite and martensite, while for medium-Mn steels retained austenite is also formed. In a present study, a wide intercritical temperature range was applied to a 5% Mn steel to...journal article 2024
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Meisters, Thomas (author)VDL Weweler has developed a novel heat treatment approach for their trailing arms, which eliminates the traditional austenisation step and instead capitalises on the inherent heat used for hot-forming to austenise the steel before quenching. This not only saves energy, but surprisingly also improves the lifetime of the products. The underlying...master thesis 2023
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Atreya, V. (author)Dual-phase (DP) steels are an important class of advanced high-strength steels (AHSS) and constitute a major share of steels for the automotive industry. A microstructure consisting of hard martensite embedded in a soft ferritic matrix gives them a good combination of strength and ductility. The martensite formation in the microstructure from...doctoral thesis 2023
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van Boekel, Mark (author)High Manganese Austenitic Steel (HMnAS) is a novel steel exhibiting excellent mechanical properties at arctic temperatures. Defense Material Organisation (DMO) is interested in the feasibility of using HMnAS in their navy's ships alongside EH36 high-strength shipbuilding steel, using 307PF stainless steel weld filler metal.<br/>The feasibility...master thesis 2023
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Breukelman, H. J. (author), Hermans, M.J.M. (author), Santofimia, Maria Jesus (author), Hidalgo Garcia, J. (author)Localised laser treatments enable the creation of sophisticated austenite/martensite mesostructures in Fe–Ni–C steel with the potential of achieving enhanced mechanical performance. The control of phase topology is essential to modify the properties of these structures on demand and requires a profound understanding of the effect of the...journal article 2023
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Sierra Soraluce, A. (author), Li, G. (author), Santofimia, Maria Jesus (author), Molina-Aldareguia, J. M. (author), Smith, A. (author), Muratori, M. (author), Sabirov, I. (author)Recent studies have demonstrated the viability of quenching and partitioning (Q&P) treatment for processing martensitic stainless steels showing an improved balance of high strength and sufficient ductility. However, to date, the fatigue behaviour of these materials has not been explored. This study examines the effect of their complex...journal article 2023
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Kozłowska, Aleksandra (author), Morawiec, Mateusz (author), Petrov, R.H. (author), Grajcar, Adam (author)A novel double-step intercritical annealing (DSIA) process was conducted on Fe-0.16C-4.7Mn-1.6Al-0.2Si transformation induced plasticity (TRIP) steel. In a present study, an effect of different heating and cooling rates applied to the second intercritical annealing (IA) step on the microstructure was studied in detail by using scanning...journal article 2023
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Castro Cerda, F. (author), Goulas, Constantinos (author), Hernández, Eliseo I. (author), Sanhueza, Juan P. (author), Ros-Yanez, Tanya (author), Petrov, R.H. (author)Isothermal heat treatments below the martensite start temperature are carried out in a 0.25C-1.4Mn-1.4Si-0.32Mo steel (in wt%). The microstructural observation reveals a combination of tempered lath and plate martensite, accompanied by bainite and retained austenite. The temperature variation of the austenitic carbon content under different...journal article 2023
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Satish nair, Lakshmi (author)Studies on the impact of Hydrogen on the electrochemical and mechanical behaviour of Iron-based materials have been increasingly conducted in the past few years. This is mainly due to the ever-growing demand for sustainable energy sources, which involve Hydrogen and to meet the high structural and economic demands from the automobile sector and...master thesis 2022
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Yilmaz, A. (author), He, X. (author), Pletincx, Sven (author), Hauffman, Tom (author), Sietsma, J. (author), Gonzalez Garcia, Y. (author)The role of prior austenite grain size (PAGS) on the passive layer properties of martensitic steels is studied. Electron backscatter diffraction analysis shows that PAGS between 5 and 66 µm were obtained after applying different heat treatments. The barrier properties of passive film deteriorate with grain refinement up to 28 µm, attributed to...journal article 2022
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Dhara, S. (author), van Bohemen, Stefan M.C. (author), Santofimia, Maria Jesus (author)The development of the quenching and partitioning (Q&P) process has prompted an interest in the process of isothermal transformation in presence of a pre-existing phase such as martensite. The presence of prior martensite is known to accelerate the overall kinetics of bainite formation, both in the 1-step and 2-step Q&P process. The...review 2022
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Breukelman, H. J. (author), Santofimia, Maria Jesus (author), Hidalgo Garcia, J. (author)The realisation of sophisticated hierarchically patterned multiphase steels has the potential to enable unprecedented properties in engineering components. The present work explores the controlled creation of patterned multiphase steels in which the patterns are defined by two different crystal structures: face centre cubic or fcc (austenite)...journal article 2022
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Celada-Casero, Carola (author), Vercruysse, Florian (author), Linke, Bernd (author), Smith, Ali (author), Kok, Piet (author), Sietsma, J. (author), Santofimia, Maria Jesus (author)Quenching & Partitioning (Q&P) steels owe their good strength-ductility combinations to the martensite/austenite (α’/γ) mechanical interactions and to the formation of mechanically-induced martensite (α′<sub>mech</sub>) through the transformation-induced plasticity (TRIP) effect. An essential role is played by carbon, whose...journal article 2022
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Atreya, V. (author), van Dokkum, J.S. (author), Bos, C. (author), Santofimia, Maria Jesus (author)The volume increase and shape change during austenite to martensite transformation in dual-phase (DP) steels are largely accommodated in the microstructure by the deformation of the surrounding ferrite matrix. Accurate estimation of transformation-induced deformation of ferrite via experiments and modeling is essential for predicting the...journal article 2022
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Vercruysse, Florian (author), Claeys, Lisa (author), Depover, Tom (author), Verleysen, Patricia (author), Petrov, R.H. (author), Verbeken, Kim (author)In the present study, the effect of Niobium (Nb) on the hydrogen embrittlement resistance of Quenched and Partitioning (Q&P) steel is investigated. For this purpose, the hydrogen uptake level and its impact on the mechanical properties of a Nb-free and a 0.024 wt% Nb Q&P steel are thoroughly analysed. The hydrogen trapping capacity is...journal article 2022
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Crousen, Leon (author)A long standing research field in material science has been the trade-off between strength and ductility of steels. Advanced High Strength Steels (AHSS) aim to combine these two properties and provide steels that can increase safety and lower CO2 consumption in automotive applications, by decreasing weight. To further decrease the environmental...master thesis 2021
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de Bakker, Benne (author)Quenching and Partitioning (Q&P) is a novel steel heat treatment to create microstructures containing martensite and retained austenite. In recent years, there has been a growing interest in applying Q&P treatments to martensitic stainless steels with the aim to create stainless steels with the mechanical properties...master thesis 2021
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Koopmans, T.T.W. (author), Sietsma, J. (author), Zhao, L. (author), Santofimia, Maria Jesus (author)The quenching and partitioning (Q&P) process is a heat treatment process, aiming at the creation of steel microstructures composed of martensite and retained austenite. Herein, the thermal stability of the microstructure is investigated upon reheating steel microstructures, created with different Q&P settings, in different thermal...journal article 2021
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Atreya, V. (author), Bos, C. (author), Santofimia, Maria Jesus (author)During the production of DP steels, the volume expansion and shape change accompanying the austenite to martensite transformation is accommodated by the deformation of surrounding ferrite grains. The extent of the deformation in ferrite grains ultimately affects the mechanical properties of DP steels. Using electron backscatter diffraction...journal article 2021
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Lan, H. (author), Tang, S. (author), DU, Linxiu (author), LI, Jianping (author), van der Zwaag, S. (author)The combined effects of the initial microstructure and heating rate on ferrite recrystallization, austenite formation and transformation kinetics of a regular ferrite-martensite dual phase steel are investigated. Special attention is given to the effect of the martensite distribution on mechanical properties, particularly the bendability....journal article 2021