Article
Materials Science, Multidisciplinary
Y. Ge, Z. Que, K. Lindgren, N. Hytonen, M. Thuvander
Summary: This study investigated a narrow-gap SA508/Alloy 52 dissimilar metal weld mock-up, which is fully representative of a real nuclear component. The microstructure and carbides formed in the fusion boundary and heat affected zone can lead to brittle fracture and affect the brittle fracture behavior. However, there is limited information available on the microstructural changes and carbide formation in DMW during post-weld heat treatment and long-term thermal aging. This study analyzed the microstructure, carbide type, morphology, and size in different zones of the DMW under post-weld heat-treated and thermally-aged conditions.
MATERIALS CHARACTERIZATION
(2023)
Article
Mechanics
Sebastian Lindqvist, Zaiqing Que, Pekka Nevasmaa, Noora Hytonen
Summary: This study investigates the effect of thermal aging at 400 degrees C for up to 15,000 hours on the ductile-to-brittle transition region of an Alloy 52 dissimilar metal weld (DMW). The results show that the T0 reference temperature remains relatively unchanged, with only a 10 degrees C shift, while the T28J temperature increases by 49 degrees C and the TKIa temperature increases by 35 degrees C after aging.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Materials Science, Multidisciplinary
Byeong Seo Kong, Ji Ho Shin, Chaewon Jeong, Changheui Jang, Sung-Sik Kang
Summary: The deformation behavior of 8-ferrite in an aged austenitic stainless-steel weld was studied to understand the contribution of aging-induced nanofeatures to aging embrittlement. The strengthening effect of spinodal decomposition and G-phase precipitation was evaluated and compared using nanopillar compression tests. The results showed that the nanofeatures exhibited different stability during deformation, with G-phase being less effective as an obstacle compared to spinodal decomposition.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Chemistry, Physical
T. Zhu, Z. H. Zhong, X. L. Ren, Y. M. Song, F. J. Ye, Q. Q. Wang, Alfonso H. W. Ngan, B. Y. Wang, X. Z. Cao, Q. Xu
Summary: This study found that hydrogen alloying with a proper concentration can improve the strength and ductility of high-entropy alloys by promoting the formation of stacking faults/nanotwins at the interface. The beneficial effect is positively correlated with the hydrogen concentration at the interface.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Hongmin Ju, Shiwei Zhuo, Jing Liu, Zirui Chen, Huijie Cui, Yanli Wang, Shilei Li
Summary: The effect of thermal aging on microstructural evolution and mechanical behavior was studied using advanced instrumental analysis. The microstructure in the coarse-grained heat-affected zone transformed from martensite to martensite/bainite mixture. The micro-hardness in this zone showed a positive correlation with thermal aging time due to changes in microstructure and increased number of M23C6 precipitates. The tensile strength and elongation of dissimilar metal welds also increased with thermal aging time. However, fracture occurred on the Alloy 152 side and exhibited a ductile fracture mode.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Materials Science, Multidisciplinary
Cong Chen, Xuni Yin, Wei Liao, Yunzhong Xiang, Ming Gao, Yi Zhang
Summary: Increasing the laser scanning frequency and amplitude can improve the proportion of equiaxed grains and reduce the average diameter in the weld, leading to increased elongation. The scanning laser helps to enhance the strength of the weld fusion zone and provides a new way to improve the strength, safety, and service life of new energy power batteries through even distribution of elements and strengthening phases.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Nanoscience & Nanotechnology
Chaewon Jeong, Byeong Seo Kong, Ji Ho Shin, Junjie Chen, Qian Xiao, Changheui Jang
Summary: The long-term thermal aging behavior of a 316L austenitic stainless steel welds was investigated using different mechanical property testing methods. The activation energies were estimated and discussed in relation to the contribution of embrittled 6-ferrite to fracture and deformation.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Physical
Thorsten Michler, Fabien Ebling, Heiner Oesterlin, Carl Fischer, Ken Wackermann
Summary: Developing engineering standards for the hydrogen economy requires extensive materials testing. One method is using tubular specimens for testing. This study compares the tensile properties of X60 pipeline steel tested in high pressure gaseous hydrogen using tubular and conventional specimens.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Materials Science, Multidisciplinary
Q. Li, J. W. Mo, S. H. Ma, F. H. Duan, Y. L. Zhao, S. F. Liu, W. H. Liu, S. J. Zhao, C. T. Liu, P. K. Liaw, T. Yang
Summary: In this study, it was found that the long-standing problem of hydrogen embrittlement (HE) in metallic materials can be effectively eliminated in Fex(CrCoNi)1-x face-centered cubic (fcc) high-entropy alloys (HEAs) by triggering localized segregation of Cr at grain boundaries (GBs). Increasing the Fe concentration significantly improves the HE resistance, reduces ductility loss, and transforms the fracture mode. The increased Fe concentration promotes nanoscale Cr segregation at GBs, enhancing the GBs' cohesive strength and suppressing local hydrogen segregation, thus achieving outstanding HE resistance.
Article
Chemistry, Physical
Sudharsanan Sundaram, G. D. Janaki Ram, Murugaiyan Amirthalingam
Summary: Hydrogen embrittlement is a major concern during high-strength steel welding, and susceptibility to hydrogen embrittlement increases with weld strength. This study investigates the susceptibility of carbide-free bainitic weld metals to hydrogen embrittlement by varying the volume fractions of constituent phases. Hydrogen saturation behavior was studied using cathodic electrolytic charging and diffusible hydrogen measurements, and tensile tests were conducted to evaluate susceptibility to hydrogen embrittlement. The results demonstrate that carbide-free bainite weld metals are highly resistant to hydrogen embrittlement despite their high strength.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Nanoscience & Nanotechnology
Kazuho Okada, Akinobu Shibata, Taisuke Sasaki, Hisashi Matsumiya, Kazuhiro Hono, Nobuhiro Tsuji
Summary: This study aimed to improve the resistance against hydrogen embrittlement by increasing the concentration of carbon segregated at prior austenite grain boundary (PAGB), XPAGB, in low-carbon martensitic steels. The specimens with and without carbon segregation treatment (Non-seg and Seg specimens, respectively) had similar microstructures, except for higher XPAGB in the Seg specimen. The Seg specimen exhibited higher maximum stress and smaller fraction of intergranular fracture surface under hydrogen-charged conditions, indicating that segregated carbon suppressed hydrogen accumulation and increased cohesive energy of PAGB.
SCRIPTA MATERIALIA
(2023)
Article
Engineering, Manufacturing
Anup Kumar Maurya, Chandan Pandey, Rahul Chhibber
Summary: This study investigates the influence of heat input on microstructure evolution and mechanical properties of nitronic steel and super duplex stainless steel dissimilar welded joints. The results show that heat input has a significant impact on the hardness and mechanical properties of the welded joints.
MATERIALS AND MANUFACTURING PROCESSES
(2023)
Article
Materials Science, Multidisciplinary
Jinxin Gou, Xiao Xing, Gan Cui, Zili Li, Jianguo Liu, Xiangyuan Deng
Summary: This paper studied the hydrogen-induced cracking behavior in the coarse-grained heat-affected zone of X80 steel welds. It is shown that hydrogen significantly decreases a material's elongation and reduction of area. The hydrogen embrittlement susceptibility of the steel depends on the heat input, with higher heat inputs leading to increased susceptibility. The presence of hydrogen causes a transition in fracture mode from ductile to brittle, and the resistance to hydrogen embrittlement is influenced by the microstructures present in the steel.
Article
Nanoscience & Nanotechnology
Yuri Sugiyama, Nami Kurihara, Yuya Matsumoto, Kenichi Takai
Summary: Interstitial hydrogen and carbon atoms in iron were found to suppress the diffusion and annihilation of vacancies, resulting in vacancy stabilization. Atmospheric aging at 30 degrees C reduced small vacancies, while aging at -196 degrees C hardly caused any vacancy changes.
SCRIPTA MATERIALIA
(2021)
Article
Engineering, Mechanical
Deepshree D. Awale, V. D. Vijayanand, Atul R. Ballal, Manjusha M. Thawre, J. Ganesh Kumar, G. V. Prasad Reddy
Summary: Strength variations in a dissimilar weld joint made between 316LN stainless steel (SS) and P91 steel after creep exposure at 550 degrees C and stress of 200 MPa were estimated using automated ball indentation (ABI) test. Results showed that the creep exposure strengthened the 316LN SS side but caused a loss of strength in the P91 steel side. The ABI-derived results indicated that the intercritical-heat affected zone (IC-HAZ) of P91 steel was the weakest region across the weld after creep exposure.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Materials Science, Multidisciplinary
Ladislav Falat, Jan Kepic, Lucia Ciripova, Peter Sevc, Ivo Dlouhy
JOURNAL OF MATERIALS RESEARCH
(2016)
Article
Materials Science, Multidisciplinary
L. Falat, L. Ciripova, V. Homolova, P. Futas, P. Sevc
KOVOVE MATERIALY-METALLIC MATERIALS
(2016)
Article
Materials Science, Multidisciplinary
Ladislav Falat, Viera Homolova, Lucia Ciripova, Peter Sevc, Milan Svoboda
ADVANCES IN MATERIALS SCIENCE AND ENGINEERING
(2017)
Article
Materials Science, Multidisciplinary
P. Gogola, T. Kunikova, M. Domankova, P. Sevc, S. Tuleja, L'. Caplovic, M. Vach, J. Janovec
Article
Engineering, Mechanical
Juraj Blach, Ladislav Falat, Peter Sevc
ENGINEERING FAILURE ANALYSIS
(2009)
Article
Engineering, Mechanical
J. Blach, L. Falat, P. Sevc
ENGINEERING FAILURE ANALYSIS
(2011)
Article
Materials Science, Multidisciplinary
Marian Vach, Terezia Kunikova, Maria Domankova, Peter Sevc, L'ubomir Caplovic, Peter Gogola, Jozef Janovec
MATERIALS CHARACTERIZATION
(2008)
Article
Materials Science, Multidisciplinary
Lucia Ciripova, Ladislav Falat, Peter Sevc, Marek Vojtko, Miroslav Dzupon
Article
Materials Science, Multidisciplinary
J Janovec, A Vyrostková, P Sevc, JS Robinson, M Svoboda, J Krestanková, HJ Grabke
Article
Metallurgy & Metallurgical Engineering
J Janovec, D Grman, J Országhová, P Sevc, P Záhumensky, J Patscheider, S Tuleja, J Pecha, M Bogyó, J Blach, V Magula
CANADIAN METALLURGICAL QUARTERLY
(2002)
Article
Nanoscience & Nanotechnology
P Sevc, J Janovec, P Lejcek, P Záhumensky, J Blach
SCRIPTA MATERIALIA
(2002)
Article
Chemistry, Physical
J Janovec, D Grman, J Perhácová, P Lejcek, J Patscheider, P Sevc
SURFACE AND INTERFACE ANALYSIS
(2000)
Article
Materials Science, Multidisciplinary
J Janovec, V Vokal, J Krestankova, P Sevc, A Vyrostkova
KOVOVE MATERIALY-METALLIC MATERIALS
(2003)
Article
Materials Science, Multidisciplinary
J Blach, P Sevc, J Janovec
KOVOVE MATERIALY-METALLIC MATERIALS
(2003)