Article
Materials Science, Multidisciplinary
Seong Hoon Kim, Ji Hoon Kim, Jae Hoon Lee, Dong-Woo Suh, Jae Sang Lee
Summary: The present study investigates the phase constitution of a medium-carbon Q&P steel by comparing various approaches to the transformation stasis of bainitic ferrite and finds that the modified GEB approach can predict the phase constitution most accurately.
METALS AND MATERIALS INTERNATIONAL
(2022)
Article
Nanoscience & Nanotechnology
Hojun Gwon, Sung-Ho Kim, Jong Jin Jeon, Sung-Joon Kim
Summary: The study revealed that after aging at 400 degrees C for 30 minutes, cold-rolled 16Cr-5Ni supermartensitic stainless steel showed a significant increase in yield strength, a decrease in strain hardening rate, delayed martensitic transformation, and redistribution of carbon atoms.
SCRIPTA MATERIALIA
(2021)
Article
Materials Science, Multidisciplinary
Puchang Cui, Tao Xia, Yuqi Wang, Changhao Jia, Hongli Wang, Qingqing Bai, Zhihong Zhang, Huaibei Zheng, Zhonghong Lai, Yong Liu, Jingchuan Zhu
Summary: The isothermal transformation kinetics and microstructural evolution of reversed austenite in PH13-8Mo steel were systematically investigated. The complete elimination of residual austenite and the critical temperatures of martensite transformation were determined. The fraction of reversed austenite increased with temperature. The interfacial behavior and diffusion coefficients of alloying elements were also studied.
MATERIALS CHEMISTRY AND PHYSICS
(2024)
Article
Chemistry, Physical
Victor Ruiz-Jimenez, Jose A. Jimenez, Francisca G. Caballero, Carlos Garcia-Mateo
Summary: The evolution of bainitic ferrite plate thickness was studied in two nanostructured steels, showing an unexpected thickening of the plate during transformation contrary to existing predictions. This study tracked the changes in relevant parameters influencing microstructure scale, austenite YS, transformation driving force, and transformation rate evolution.
Article
Materials Science, Multidisciplinary
John S. S. Aristeidakis, Gregory N. N. Haidemenopoulos
Summary: In this study, a physically based constitutive and transformation kinetics model is presented to describe the formation of stress-assisted and strain-induced martensite and twin in steels containing austenite. The deformation behavior of different phases is modeled using dislocation density, and the macroscopic response of the material is calculated using a homogenization method. The model predicts the fractions of different martensite and twin phases and can be used in the design of new alloys with exceptional properties.
Article
Materials Science, Multidisciplinary
Henry Martin, Peter Amoako-Yirenkyi, Aarne Pohjonen, Nana K. Frempong, Jukka Komi, Mahesh Somani
Summary: The article introduces a statistically developed model for austenite decomposition during cooling, which incorporates two-way interactions of alloying elements as add-on terms. This model can predict phase transformation temperatures and critical cooling rates for the formation of polygonal ferrite, bainite or martensite in steel production.
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Yisi Song, Chuanwei Li, Yu Liao, Jianfeng Gu
Summary: This study investigated the mechanical stability of two types of reversed austenite, film-like and blocky reversed austenite, which were obtained after tempering for different time at 620 degrees C in 16%Cr-5%Ni super martensitic stainless steel. Synchrotron high-energy X-ray diffraction combined with in-situ tensile testing was performed. The results indicate that most of the blocky reversed austenite transformed into martensite early at the elastic stage, while the stress induced martensitic transformation of film-like reversed austenite mainly occurred after yield. The poor mechanical stability of blocky reversed austenite was attributed to the increase in chemical driving force caused by the lower degree of Ni enrichment, the decrease in strain energy due to matrix softening, and the lower interfacial energy due to the smaller specific surface area.
Article
Nanoscience & Nanotechnology
A. Sierra-Soraluce, G. Li, M. J. Santofimia, J. M. Molina-Aldareguia, A. Smith, M. Muratori, I. Sabirov
Summary: This article investigates the effect of chemistry and heat treatment parameters on the microstructure and properties of Q&P treated martensitic stainless steels. It is demonstrated that these steels show a good combination of enhanced strength and sufficient tensile ductility, with the ability of the martensitic matrix to accumulate plastic deformation playing an important role. The relationship between the Q&P process, microstructure, and properties is discussed.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Nanoscience & Nanotechnology
Wei Chen, J. H. Luan, Lianyong Xu, Yongdian Han, Lei Zhao, Ji-Jung Kai, Bo Xiao, Hongyang Jing
Summary: Additively manufactured 15-5 PH stainless steels with reversed nano-scale austenite dispersed in martensitic matrix exhibit enhanced strength-ductility combination and fatigue resistance, attributed to the crack closure effect caused by transformation-induced volume expansion and the transformation-induced plasticity effect.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Engineering, Civil
Filip Kateusz, Adelajda Polkowska, Wojciech Polkowski, Konrad Chrzan, Krzysztof Jaskowiec, Pawel Sokolowski, Amaya Igartua, Josu Leunda, Magdalena Bisztyga-Szklarz, Tomasz Dudziak, Jerzy Jedlinski
Summary: The study investigates the impact of recycling stainless steel waste on the microstructure and chemical composition of resulting powders. It demonstrates the utility of recycling stainless steel into high-grade powders suitable for additive manufacturing. The results show that the properties and hardness of the powders vary with the particle diameter.
ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING
(2023)
Article
Nanoscience & Nanotechnology
Xilin Xiong, Jun He, Huihui Zhi, Stoichko Antonov, Cheng Zhang, Yong Zhong, Yanjing Su
Summary: Annealing treatment below austenite start transformation temperature can improve the mechanical properties of martensitic stainless steel by stabilizing retained austenite and increasing its elongation.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Oscar Rios-Diez, Ricardo Aristizabal-Sierra, Claudia Serna-Giraldo, Adriana Eres-Castellanos, Carlos Garcia-Mateo
Summary: The study shows that nanobainitic carbo-austempered cast steels exhibit better fatigue performance than traditional carburized-Q&T steels, which is attributed to the differences between the microstructures, the role of ferrite and austenite crystals in crack propagation, the importance of prior austenite boundaries and block boundaries as crack deflectors, and how all these parameters ultimately affect the fatigue behavior.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Snehashish Tripathy, P. S. Manoranjan Jena, Vikash Kumar Sahu, Sudip Kumar Sarkar, Sarita Ahlawat, Aniruddha Biswas, Bhupeshwar Mahato, Soumitro Tarafder, Sandip Ghosh Chowdhury
Summary: Bulk nano-pearlitic microstructure with interlamellar spacing below 100 nm was achieved by rapidly undercooling a hypereutectoid multicomponent steel. The partitioning kinetics of substitutional components between ferrite and cementite were analyzed through experiments and simulations, showing that manganese had the fastest kinetics in the early stages, followed by chromium, while manganese and silicon had much faster rates compared to chromium in the completion stages of partitioning.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Gokhan Polat, Hasan Kotan
Summary: Stainless steels with different Fe/Cr/Ni ratios were produced by mechanical alloying at room and cryogenic temperatures. The effects of alloying temperature on martensitic transformation, the reversion of deformation-induced martensite, and cooling rate on thermal stability of reversed austenite were investigated. Results showed that low nickel-containing steel underwent nearly complete martensitic transformation, with partial transformation at cryogenic temperatures. Additionally, slower cooling rates increased thermal stability of reversed austenite.
METALS AND MATERIALS INTERNATIONAL
(2021)
Article
Metallurgy & Metallurgical Engineering
Fei Guo, Cheng-Wu Zheng, Pei Wang, Dian-Zhong Li, Yi-Yi Li
Summary: It is found in this study that under low-oxygen conditions, the addition of trace rare earth elements can significantly influence the nucleation, morphology, and growth of ferrite in Fe-0.14%C alloy, by slowing down carbon diffusion and decreasing grain boundary energy. This research provides evidence for adjusting phase transformation and improving the mechanical properties of steels through the addition of rare earth elements.
ACTA METALLURGICA SINICA-ENGLISH LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Bo Wang, Konstantin V. V. Werner, Matteo Villa, Thomas L. L. Christiansen, Marcel A. J. Somers
Summary: AISI 304 stainless steel plate was functionally graded with symmetrical nitrogen concentration profile by high-temperature solution nitriding. The responses to plastic deformation and austenite stability were investigated by cold rolling. The evolutions of nitrogen concentration profile, phase distribution, deformation microstructure, and hardness were characterized. The results demonstrate the influence of nitrogen content on deformation modes and stacking fault energy in Fe-Cr-Ni alloys.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2023)
Article
Metallurgy & Metallurgical Engineering
Vania M. Rodriguez, Victor Hugo Lopez-Morelos, Venkata Karthik Nadimpalli, Bue David Pedersen, Alberto Ruiz, Marcel A. J. Somers
Summary: In this study, 440C martensitic stainless steel was manufactured through spray forming technology, and the microstructural and mechanical properties were evaluated after different heat treatments. It was found that austenitizing temperature affects the deformation and fracture behavior of the steel, with higher temperatures leading to an improvement in tensile properties and a decrease in strain hardening rate. The Q-IQ-T heat treatment was effective in improving toughness and ductility without compromising strength. These results suggest that the mechanical response of the SF-440C MSS can be tailored by adjusting the heat treatment parameters for better industrial design.
STEEL RESEARCH INTERNATIONAL
(2023)
Article
Materials Science, Coatings & Films
Bo Wang, Thomas L. Christiansen, Marcel A. J. Somers
Summary: Duplex stainless steel 2205 was annealed to adjust the phase fractions, and then high-temperature solution nitriding was conducted. The influence of phase fractions on nitriding kinetics and the evolution of microstructure during solution nitriding were analyzed using various characterization techniques. It was found that higher ferrite phase fraction resulted in finer grains of nitrogen-stabilized austenite. The slower grain growth in higher ferrite phase fractions could be attributed to phase distribution, alloying element partitioning, and pinning effect by M2N nitrides.
SURFACE & COATINGS TECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Nikolaj G. Henriksen, Konstantinos Poulios, Marcel A. J. Somers, Thomas L. Christiansen
Summary: Medical devices require unique identification markings for traceability, commonly applied through laser marking directly onto metallic devices. However, the effects of laser marking on material performance are largely unknown. This study investigates the effects of laser marking on common titanium alloys used in the medical industry, revealing surface melting, the formation of cracks, and a significant reduction in fatigue strength.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Frank Niessen, Wei Li, Konstantin V. Werner, Song Lu, Levente Vitos, Matteo Villa, Marcel A. J. Somers
Summary: Intrinsic stacking fault energy (SFE) values of γ-Fe and AISI 304 stainless steels were determined using ab initio calculations, taking into account the magnetic properties and finite temperature effects. The SFE of non-magnetic γ-Fe increases significantly when paramagnetism is included. Interstitial alloying of non-magnetic γ-Fe leads to a linear increase in SFE, while interstitial alloying of paramagnetic γ-Fe has a slower impact. The SFE of paramagnetic interstitial-free AISI 304 is similar to that of paramagnetic γ-Fe, and both alloys are stabilized by interstitial alloying. The calculated nitrogen content required to stabilize austenite in AISI 304 agrees well with experimental observations.
Article
Materials Science, Multidisciplinary
H. L. Che, X. Yang, M. K. Lei, Marcel A. J. Somers
Summary: Both experimental and theoretical studies have confirmed that disordered expanded austenite, gamma N, and ordered expanded austenite, gamma'N, consist of Cr-N short-range ordering (SRO) and Fe4N-like long-range ordering (LRO) in addition to Cr-N SRO, respectively. However, the transition from gamma N to gamma'N during low temperature nitriding has not been fully understood. In this study, four Fe-Cr-Ni alloys were investigated to explore the evolution from gamma N to gamma'N using transmission electron microscopy (TEM). Results showed that Fe4N-like LRO exists as small ordered domains separated by antiphase boundaries, and the size of the ordered domains is influenced by the Cr and N content in the alloys. A 3-dimensional Cellular Automaton (CA) simulation was developed to simulate the nucleation, growth, and coarsening of the ordered domains, and the simulated distributions were consistent with the TEM results.
Article
Chemistry, Physical
Yawei Peng, Han Duan, Yajian Feng, Jianming Gong, Marcel A. J. Somers
Summary: The effect of low-temperature gaseous carburization on AlxCoCrFeNi high-entropy alloys was investigated. It was found that carburization successfully hardened the surface region of the alloys, resulting in a hardened case with varying hardness and depth based on the Al content. The surface hardness originated from a carbide-free carbon-enriched case, with the composition of the case depending on the Al content.
Article
Materials Science, Coatings & Films
Yajian Feng, Han Duan, Zhenxu Zhao, Zhe Liu, Yawei Peng, Jianming Gong, Marcel A. J. Somers
Summary: Low-temperature gaseous carburization (LTGC) was used to modify the surface properties of austenitic stainless steel fabricated by Laser Powder Bed Fusion (LPBF). During LTGC, a carburized case of expanded austenite forms at the surface, which has high surface carbon content (-2.5 wt%), high nano hardness (-12.6 GPa), large compressive residual stresses (from-2.4 GPa to-3.2 GPa), and is free of carbide precipitates. X-ray diffractometry (XRD) measurements showed anisotropic residual stresses in the expanded austenite zones, which are suggested to be caused by grain-shape anisotropy and hierarchical microstructures resulting from L-PBF.
SURFACE & COATINGS TECHNOLOGY
(2023)
Article
Materials Science, Coatings & Films
Andreas F. K. Korkel, Morten S. Jellesen, Morten Foss, Marcel Ceccato, Marcel A. J. Somers, Thomas L. Christiansen
Summary: This study investigates the controlled formation of white rutile surface layers on commercially pure titanium by gaseous thermochemical oxidation. The formed oxide layers were analyzed using various techniques, including microscopy, spectroscopy, and analysis of physical properties. The study finds that a two-step oxidation process results in the growth of robust, dense, adherent white titanium oxide layers. The first step involves oxidation in a CO/CO2 atmosphere, while the second step is performed in N2/N2O. Carbon is incorporated into the oxide layer during the first step and is then oxidized and removed during the second step, resulting in aesthetically pleasing white oxide layers.
SURFACE & COATINGS TECHNOLOGY
(2023)
Article
Engineering, Mechanical
H. K. Danielsen, M. Villa, F. Gutierrez Guzman, S. Faester, K. V. Dahl, R. H. Vegter, O. L. Jensen, T. S. Hummelshoj, B. Lehmann, G. Jacobs, M. A. J. Somers, T. L. Christiansen
Summary: A novel WEC resistant bearing steel solution has been developed through a custom heat treatment, which showed improved performance in testing compared to standard bearing steel.
Article
Materials Science, Multidisciplinary
Frank Niessen, Konstantin Werner, Wei Li, Song Lu, Levente Vitos, Matteo Villa, Marcel A. J. Somers
Summary: Density Functional Theory (DFT) is a commonly used method for determining stacking fault energy (SFE) in fcc metals and alloys. However, the determination of SFE in interstitial alloys with elements like carbon, nitrogen, and hydrogen has been limited. This study proposes a new method based on the axial interaction model that allows for rapid and accurate mapping of SFE for various interstitial contents. The method has been validated and shown to be computationally efficient, and it also reveals the non-additive contribution of certain elements to the SFE.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Matteo Villa, Flemming B. Grumsen, Frank Niessen, Thomas Dahmen, Lingfei Cao, Michael Reich, Olaf Kessler, Xiaoxu Huang, Marcel A. J. Somers
Summary: The present investigation studied the effects of austenite aging on precipitation hardening martensitic stainless steel. It was found that austenite aging promotes the formation of copper clusters and particles, affects the kinetics and substructure of martensite formation, and significantly strengthens the material. The contribution of precipitates to the strength of martensite was interpreted using the Russell-Brown model.
