Article
Nanoscience & Nanotechnology
Huansheng He, Jingwen Zhang, Liming Yu, Qiuzhi Gao, Chenxi Liu, Zongqing Ma, Huijun Li, Yongchang Liu, Hui Wang
Summary: This study systematically investigated the microstructure evolution and creep deformation behavior of G115 steels with Cu-rich phases at elevated temperatures. The results showed that the Cu-rich phases played a vital role in retarding microstructural degeneration and improving creep strength, which is of great significance for the application and improvement of steel materials.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Taotao Ruan, Junjie Shen, Bo Li, Zhihang Zhao, Dechang Zhang
Summary: The study analyzed the strengthening mechanism and effect of Fe2Nb and Fe2W Laves phase alloys in a ferritic matrix, indicating that Fe2Nb-type Laves phase may be more suitable as a strengthener in the ferritic matrix compared with Fe2W-type.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Physical
Bernd Kuhn, Michal Talik
Summary: HiperFer steels are a new type of heat-resistant, fully ferritic materials with increased mechanical strength and improved resistance to steam oxidation. Heat treatment was found to significantly improve the creep performance of the material, leading to a 100% increase in rupture time at 650 degrees C and a creep stress of 100 MPa.
Article
Materials Science, Multidisciplinary
Sharhid Jabar, John A. Siefert, Martin Strangwood, Geoff D. West
Summary: This paper quantitatively assessed the micro-scale chemical homogeneity of two ex-service boiler components using high sensitivity chemical mapping and found pronounced compositional variation in larger elements Mo and Nb. The effect of this micro-segregation on local variations in Laves phase particle characteristics was also investigated using SEM images, showing a significant difference between positively and negatively Mo-segregated regions. This result was consistent with the thermodynamic equilibrium predictions of the phase content based on the observed level of segregation.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Bernd Kuhn, Michal Talik
Summary: This paper discusses the influence of forming parameters on the microstructure and achievable creep properties of high-performance ferritic stainless steels. Thermomechanical treatment is shown to effectively enhance the creep strength of the materials, offering potential cost savings in component production.
Review
Materials Science, Multidisciplinary
Yang Zhao, Hou-Long Liu, Liang-Liang Wei, Li-Qing Chen
Summary: Heat-resistant ferritic stainless steels are widely used in various industries due to their excellent performance. The research progress in terms of high-temperature strength, formability, high-temperature oxidation resistance, and creep performance has been summarized, and suggestions for alloy composition design and microstructure optimization have been provided.
Article
Materials Science, Multidisciplinary
Bo Xiao, Haokai Dong, Tao Yang, Shaofei Liu, Shenbao Jin, Boxuan Cao, Yongdian Han, Lei Zhao, Xiawei Yang, Gang Sha, Lianyong Xu
Summary: We present two typical morphologies (elongated- and blocky-shaped) of the Laves phase in tempered martensite ferritic steels during creep process, which are formed through two independent paths: grain boundaries and neighboring M23C6. The presence of multi-element segregation (Cr, Mn, Si, and W) at grain boundaries and adjacent M23C6 provides a source of Laves phase formation. Additionally, different growth mechanisms play crucial roles in the formation of these two morphologies. Our findings enhance the understanding of Laves phase heterogeneous precipitation and offer insights for the development of novel heat-resistant steels with superior creep strength.
MATERIALS RESEARCH LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Mingkun Jiang, Ying Han, Tong Zhang, Jiapeng Sun, Guoqing Zu, Hua Chen, Xu Ran
Summary: The precipitation behavior of 17Cr-0.86Si-1.2Cu-0.5Nb ferritic stainless steel during isothermal aging was studied, showing different precipitation of Cu-rich and Nb-rich phases at different temperatures. The hardness change with aging time at different temperatures was also investigated.
MATERIALS CHARACTERIZATION
(2021)
Article
Materials Science, Multidisciplinary
Ming Shu, Qin Zhou, Gang Li, Xue Liang, Hongliang Ming, Yongduo Sun, Xiaodong Lin, Jun Xiao
Summary: The addition of a trace amount of 20 ppm B significantly improved the creep performance of the 2.5Al-AFA alloy at 650 degrees C. Boron (B) preferentially distributed in the Laves phase and gradually diffused into the surrounding Laves phase at grain boundaries (GBs) through M23C6. Creep cracks propagated mainly along GBs, with the a phase serving as initiation sites. B accelerated the precipitation of Laves phase, resulting in improved GB strengthening and more effective suppression of a phase growth.
MATERIALS CHARACTERIZATION
(2023)
Article
Materials Science, Multidisciplinary
Hui-Hu Lu, Hong-Kui Guo, Wei Liang
Summary: In this study, a dissolution heat treatment was applied to restore the plasticity of embrittled superferritic stainless steel caused by the precipitation of sigma-phase, chi-phase, and Laves phase. The dissolution behavior of the brittle precipitation phases, as well as their effects on the mechanical properties, were investigated. It was observed that the plasticity of the tested steels was recovered after dissolution treatment, and the fracture mode changed from brittle to toughness.
MATERIALS CHARACTERIZATION
(2022)
Article
Materials Science, Multidisciplinary
Jaromir Dlouhy, Eva Chvostova, Crtomir Donik
Summary: The formation of Laves phase was studied in experimental 10Cr-3 W-3Co creep-resistant steel, with comparisons made between thermal and creep exposure. Image analysis of micrographs was used to quantitatively analyze the Laves phase content, particle size, and morphology. Significant differences were observed, with thermal exposure resulting in the nucleation and coarsening of fine Laves phase particles, while creep exposure induced the formation of coarse particles from the early stages.
Article
Materials Science, Multidisciplinary
Jaromir Dlouhy, Eva Chvostova, Zbysek Novy
Summary: The evolution and coarsening of Laves phase in 10Cr-3W-3Co-1Mo nitrogen free creep resistant steels at temperature 650 degrees C was quantified. The influence of B content on Laves phase evolution and the formation of thin Laves phase films were investigated. The tensile tests at 650 degrees C did not show any detrimental effect of these films on the material plasticity.
Article
Chemistry, Physical
Maohong Yang, Zheng Zhang, Linping Li
Summary: This paper investigated the evolution of microstructure and microhardness in the G115/Sanicro25 dissimilar steel welded joint during the creep process. The results showed that fracture locations were in the fine-grain heat-affected zone, and the cavities were related to the second phase.
Article
Nanoscience & Nanotechnology
A. Fedoseeva, I Nikitin, N. Dudova, R. Kaibyshev
Summary: The study investigated the coarsening of Laves phase in a 10% Cr-3% Co-3% W steel at 923 K, revealing that the strain during creep accelerates the depletion of tungsten from the ferrite matrix and the precipitation of Laves phase. The coarsening of Laves phase follows Ostwald ripening and is controlled by grain boundary diffusion, with growth observed on different boundaries and a significant contribution to creep behavior from dense chains of Laves phase on lath boundaries.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Hiroshi Oka, Takashi Tanno, Yasuhide Yano, Satoshi Ohtsuka, Takeji Kaito, Naoyuki Hashimoto
Summary: 9Cr oxide dispersion strengthened steels with different nitrogen concentrations were investigated for their creep behavior at 973K. It was found that the creep strength decreased significantly with increasing nitrogen concentration. Microstructural analysis revealed the presence of coarse Y-rich inclusions in the specimens with higher nitrogen concentrations. Furthermore, rows of creep voids were observed near the rupture part of the specimens, and their fraction increased with increasing nitrogen concentration.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Engineering, Mechanical
T. Fischer, B. Kuhn
INTERNATIONAL JOURNAL OF FATIGUE
(2020)
Article
Materials Science, Multidisciplinary
Bernd Kuhn, Michal Talik, Torsten Fischer, Xiuru Fan, Yukinori Yamamoto, Jennifer Lopez Barrilao
Article
Chemistry, Multidisciplinary
Torsten Fischer, Bernd Kuhn, Detlef Rieck, Axel Schulz, Ralf Trieglaff, Markus Benjamin Wilms
APPLIED SCIENCES-BASEL
(2020)
Article
Nuclear Science & Technology
S. Moeller, R. Krug, R. Rayaprolu, B. Kuhn, E. Jou, A. Kreter
NUCLEAR MATERIALS AND ENERGY
(2020)
Article
Materials Science, Multidisciplinary
Xiuru Fan, Bernd Kuehn, Jana Poepperlova, Wolfgang Bleck, Ulrich Krupp
Article
Chemistry, Multidisciplinary
Bastian Blinn, David Goerzen, Torsten Fischer, Bernd Kuhn, Tilmann Beck
APPLIED SCIENCES-BASEL
(2020)
Article
Chemistry, Multidisciplinary
Bernd Kuhn, Jennifer Lopez Barrilao, Torsten Fischer
APPLIED SCIENCES-BASEL
(2020)
Article
Chemistry, Multidisciplinary
Xiuru Fan, Bernd Kuhn, Jana Poepperlova, Wolfgang Bleck, Ulrich Krupp
APPLIED SCIENCES-BASEL
(2020)
Article
Materials Science, Multidisciplinary
Mujin Yang, Daniel J. M. King, Ivan Postugar, Yuren Wen, Junhua Luan, Bernd Kuhn, Zengbao Jiao, Cuiping Wang, M. R. Wenman, Xingjun Liu
Summary: A series of G-phase strengthened ferritic stainless steels Fe-20Cr-3Ni-3Si-X were characterized after aging, showing sluggish precipitation of Ni16Mn6Si7 G-phase and early precipitation of superfine Ni16Mn6Si G-phase in the Ti containing alloy. The G-phases exhibited particle coarsening without chemical composition evolution up to 96 h of aging, while a significant hardness increase was observed. The findings provide valuable insight for developing future high strength steels.
Article
Chemistry, Physical
Jana Poepperlova, Xiuru Fan, Bernd Kuhn, Ulrich Krupp
Summary: A novel thermomechanical process route was developed for fully ferritic stainless steels strengthened by Laves phase precipitates, allowing for controlled precipitation of particles and optimization of forging parameters. The up-scaling experiment from laboratory scale to industrial scale showed changes in precipitation behavior and a decrease in the precipitation strengthening effect compared to the laboratory scale.
Article
Materials Science, Multidisciplinary
Fadoua Aarab, Bernd Kuhn, Alexander Bonk, Thomas Bauer
Summary: Concentrated solar power (CSP) and thermal energy storage (TES) are promising renewable energy technologies that utilize molten salts for heat transfer and storage. Challenges lie in the thermal stability of the salts and their corrosive effects on structural materials, requiring careful material selection and improvement in structural properties.
Article
Chemistry, Multidisciplinary
Torsten Fischer, Bernd Kuhn, Xiuru Fan, Markus Benjamin Wilms
Summary: This study developed a customized steel based on HiperFer for additive manufacturing, which demonstrated great performance potential through in-build heat treatment and tailored microstructure to counteract manufacturing flaws. The additive manufacturing process also enabled the reduction of grain size, leading to increased plastic deformation.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Physical
Torsten Fischer, Bernd Kuhn
Summary: Increased cyclic loading in thermal energy conversion systems requires new materials with higher fatigue resistance. This study compares the thermomechanical fatigue resistance and long crack propagation of grade 92 steel and Crofer 22H, a ferritic-martensitic steel and a fully ferritic stainless steel. Crofer 22H showed improved resistance to fatigue and steam oxidation up to 650 degrees C, with its main mechanisms being increased stability of grain structure and dynamic precipitation strengthening.
Article
Materials Science, Multidisciplinary
Bernd Kuhn, Michal Talik
Summary: This paper discusses the influence of forming parameters on the microstructure and achievable creep properties of high-performance ferritic stainless steels. Thermomechanical treatment is shown to effectively enhance the creep strength of the materials, offering potential cost savings in component production.
Article
Nuclear Science & Technology
M. Reinhart, S. Moller, A. Kreter, M. Rasinski, B. Kuhn
Summary: This study investigates the impact of tungsten content, sample temperature, and ion impact energy on the sputtering yield of reduced-activation ferritic martensitic steels through PSI-2 deuterium plasma exposures. Results show a reduction in sputtering yield under certain exposure conditions, indicating a possible protective effect of tungsten.
NUCLEAR MATERIALS AND ENERGY
(2022)
