Article
Materials Science, Multidisciplinary
Ping Fan, Xinbao Liu, Jinye Peng, Lin Zhu, Kai Zhang
Summary: This study investigated the creep damage of 9Cr-1Mo steel using nonlinear Lamb waves, and found that the measured acoustic nonlinearity parameter is strongly dependent on the creep state. The hierarchical microstructure of 9Cr-1Mo steel evolves during creep. By applying analytical models and kinetics of microstructure evolution, the predominant component of acoustic nonlinearity during the creep process was successfully identified.
MATERIALS CHARACTERIZATION
(2021)
Article
Engineering, Multidisciplinary
Takashi Honda, Takuya Fukahori, Takumi Tokiyoshi, Yasuharu Chuman, Toshihide Igari, Alan C. F. Cocks
Summary: This paper discusses the prediction of residual life for Type IV creep failure in Ultra Super Critical (USC) plants by considering the increase of creep void density and the influence of stress state in welded joints with non-uniform weld metal materials, heat affected zone (HAZ) and base metal, compared to experimental results at 650 degrees C.
INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING
(2021)
Article
Nanoscience & Nanotechnology
Yatindra Kumar, Manmath Kumar Dash, A. Moitra, G. Sasikala, Shaju K. Albert
Summary: This study quantifies the improvement in creep crack growth resistance in the heat-affected zone of boron-added modified 9Cr-1Mo steel welds at high temperatures. It demonstrates that the addition of boron can significantly reduce crack growth rates, decrease creep damage, and enhance resistance to creep crack growth.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
Amitava Ghatak, Puthuveettil Sreedharan Robi
Summary: The creep behavior of high Cr austenitic stainless steel was investigated at different temperatures and stress levels. The study found a correlation between the minimum creep rate and rupture time. Microstructural analysis revealed the failure mechanisms during creep. A critical continuum damage mechanics approach was used to evaluate the safety of the creep behavior.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Engineering, Multidisciplinary
J. Veerababu, Sunil Goyal, J. Vanaja, A. Nagesha, M. Vasudevan
Summary: The study on the creep-fatigue interaction behavior of modified 9Cr-1Mo steel reveals that the ASME code provides a more conservative design approach for this alloy.
INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING
(2021)
Article
Materials Science, Multidisciplinary
T. Sakthivel, C. R. Das, K. Laha, G. Sasikala
Summary: The boron containing modified 9Cr-1Mo steel (P91B-IC) exhibited higher creep rupture strength and lower minimum creep rate compared to the boron free modified 9Cr-1Mo steel (P91-IC) after intercritically heat-treated at 923K.
METALS AND MATERIALS INTERNATIONAL
(2021)
Article
Engineering, Multidisciplinary
Uijeong Ro, Sangyeop Kim, Yonghwi Kim, Moon Ki Kim
Summary: This study evaluates the lifespan of creep-fatigue interaction through finite element analyses, employing Voronoi tessellation method and damage models to describe creep and fatigue damaging mechanisms. New criteria for creep-fatigue life evaluation were proposed based on the results, which were between conventional standards.
INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING
(2021)
Article
Engineering, Multidisciplinary
Naoki Matsubara, Masao Sakane, Takamoto Itoh, Rui Kosaka
Summary: This study examined creep damage in a biaxially creep-damaged Mod.9Cr-1Mo component through uniaxial miniature creep testing, and found that the linear cumulative creep damage rule provided an unconservative estimate for the remaining life of the biaxially damaged cruciform specimen.
INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING
(2021)
Article
Engineering, Mechanical
Nasrul Azuan Alang, Lei Zhao, Kamran Nikbin
Summary: A new local constraint-based damage model, incorporating the Monkman-Grant ductility, was proposed to predict creep damage and rupture in metallic materials under various stress states. The model showed good agreement with experimental data and provided an alternative to fracture strain measurement. It was found that the location of maximum creep damage depends on factors such as creep time, geometry, and notch acuity level, with different initiation points observed for sharp and rounded notches.
JOURNAL OF STRAIN ANALYSIS FOR ENGINEERING DESIGN
(2022)
Article
Materials Science, Multidisciplinary
Sumit Kumar, Anish Karmakar, Sumeer K. Nath
Summary: Hot forged 1Cr-1Mo and 9Cr-1Mo steels are increasingly used in turbine rotor manufacturing for steam power plants, requiring precise control of processing parameters for defect-free products. A comparative study analyzed the hot deformation behavior of both steels, determining flow stress behavior, activation energy, Zener-Hollomon parameter, and critical conditions for dynamic recrystallization. The study also focused on the comparison of dynamically recrystallized austenite volume fraction with respect to true strain. Microstructural evaluation and characterization were conducted to validate the kinetics of DRX and softening mechanism.
METALS AND MATERIALS INTERNATIONAL
(2021)
Article
Chemistry, Physical
R. Rejeesh, Ankita Bhattacharya, Chandan Haldar, Rahul Mitra, Debalay Chakrabarti, C. R. Das, Shaju K. Albert, Arun Kumar Bhaduri
Summary: The systematic study on modified 9Cr-1Mo steel revealed the combined effect of B and N addition on microstructural stability and creep resistance. The best creep resistance was observed in the steel with 70 ppm B and 108 ppm N, while either too low B content or too high N content affected the precipitate stability and creep resistance of the steel.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Takashi Honda, Takuya Fukahori, Takumi Tokiyoshi, Toshihide Igari, Kimihiko Tominaga, Alan C. F. Cocks
Summary: This study investigates the influence of the ratio of crack initiation and crack propagation life on the residual life prediction of mod. 9Cr-1Mo steel welds under Type IV creep damage. The creep void density distribution and failure process are predicted for different types of welds in pipes and nozzles, and compared with experimental results. The influence of stress ratio on circumferential welds is also examined.
MATERIALS AT HIGH TEMPERATURES
(2022)
Article
Materials Science, Multidisciplinary
Lizhen Tan, Weicheng Zhong, Ying Yang, Kevin G. Field, Niyanth Sridharan, Andrew T. Nelson
Summary: Limited studies have evaluated the creep behavior of additively manufactured ferritic-martensitic steels. This study investigated the creep behavior of a 9Cr FM steel fabricated by powder blown directed energy deposition technique. The results showed a threshold temperature between 600 and 625 degrees C, below which the steel exhibited better creep resistance compared to other steels. The creep behavior and fracture surface morphology also differed at temperatures above and below the threshold.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Prerna Mishra, N. C. Santhi Srinivas, Vakil Singh
Summary: This study compares the ratcheting fatigue life of modified 9Cr-1Mo steel and Inconel alloy 617 (IN-617) under the same stress conditions, and finds that uniform plastic strain plays a dominant role in the ratcheting fatigue resistance of materials. The accumulated plastic strain in IN-617 is significantly higher than that in modified steel, resulting in a longer ratcheting fatigue life. Therefore, uniform strain can be considered an important parameter for selecting materials for tubular products in power plants.
Article
Materials Science, Multidisciplinary
Prerna Mishra, R. S. Rajpurohit, N. C. Santhi Srinivas, G. V. S. Sastry, Vakil Singh
Summary: This study investigates the fatigue behavior and fracture characteristics of steel under asymmetric cyclic loading, finding that plastic strain increases with mean stress and stress amplitude, leading to reduced cyclic life. However, an increase in stress rate reduces accumulated plastic strain and increases cyclic life. Microstructural changes were observed with an increase in the three parameters, showing a transition from lath martensitic structure to subgrain structure, along with dislocation cells and forest dislocations. Scanning electron microscopy revealed unique features of fractured specimens, with progressive reduction in diameter towards the fracture-end, fatigue striations on the tapered circumferential surface and dimples on the fracture surface.
METALS AND MATERIALS INTERNATIONAL
(2021)
Article
Nanoscience & Nanotechnology
Ahmad Mirzaei, Peter D. Hodgson, Xiang Ma, Vanessa K. Peterson, Ehsan Farabi, Gregory S. Rohrer, Hossein Beladi
Summary: This study investigated the influence of parent austenite grain refinement on the intervariant boundary network in a lath martensitic steel. It found that refining the parent austenite grain led to a decrease in the fraction of certain boundaries in the martensite and an increase in the connectivity of low energy boundaries, ultimately improving the impact toughness.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
N. L. Church, C. E. P. Talbot, L. D. Connor, S. Michalik, N. G. Jones
Summary: Metastable beta Ti alloys based on the Ti-Nb system have attracted attention due to their unique properties. However, the unstable cyclic behavior of these alloys has hindered their widespread industrial use. Recent studies have shown that internal stresses, including those from dislocations, may be responsible for this behavior. This study demonstrates that inter-cycle thermal treatments can mitigate the unstable cyclic behavior, providing a significant breakthrough in our understanding of Ti-Nb superelastic materials.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Di Zhao, Chenchen Zhao, Ziyang Xiu, Jiuchun Yan
Summary: This study proposes a novel strategy for achieving the bonding of SiC ceramic and Al alloy using ultrasound. The ultrasound promotes the dissolution of Al into the solder, activating the solder and triggering the interfacial reaction between SiC ceramic and solder. With increasing ultrasonic duration, the bonding between SiC and Al transitions from partial to full metallurgical bonding.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Kang Du, Yang Zhang, Guangda Zhao, Tao Huang, Liyuan Liu, Junpeng Li, Xiyu Wang, Zhongwu Zhang
Summary: This paper systematically investigated the evolution of microstructure in Fe-Ni-Co-Al polycrystalline alloys and its effects on mechanical properties. The results revealed that the migration of grain boundaries in different processes is driven by different factors, which impacts the grain orientation and precipitate formation. In the process of directional recrystallization, grains with specific orientations grow in the grain boundary region and form the dominant orientation, while grains with lower migration rate form the minor orientation. The alloy produced through directional recrystallization exhibited good recoverable strain and superelastic strain, while the alloy produced through solid solution treatment showed no evident superelastic behavior.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Edohamen Awannegbe, Liang Chen, Yue Zhao, Zhijun Qiu, Huijun Li
Summary: This study employed laser metal deposition to additively manufacture Ti-15Mo wt% alloy, and subsequently subjected it to post-fabrication uniaxial thermomechanical processing. The results showed that different zones in the microstructure remained after processing, and deformation mechanisms mainly involved slip and martensite formation. The compressive mechanical properties were found to be dependent on strain rate, with higher flow stress and compressive strength observed at higher strain rates. Grain structure homogenisation was not achieved, leading to anisotropic tensile properties.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Reza Khatib Zadeh Davani, Enyinnaya George Ohaeri, Sandeep Yadav, Jerzy A. Szpunar, Jing Su, Michael Gaudet, Muhammad Rashid, Muhammad Arafin
Summary: This research aims to investigate the effect of roughing and finishing reductions on crystallographic texture. The results show significant heterogeneity in the centerline region, with higher intensity of certain textures. Drop Weight Tear Test indicates that steel specimens with lower and medium reductions exhibit superior low-temperature impact toughness compared to steel with higher reductions. The electrochemical hydrogen charging experiments confirm the presence of internal hydrogen cracks only in steel with lower and medium reductions.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Flavio De Barbieri, Denis Jorge-Badiola, Rodrigo Allende, Karem Tello, Alfredo Artigas, Franco Perazzo, Henry Jami, Juan Perez Ipina
Summary: This study examines the effect of Cr additions on the mechanical behavior of TWIP steel at temperatures ranging from 25°C to 350°C. The results indicate that different temperature-dependent strengthening mechanisms, including mechanical twinning, Dynamic Strain Aging, and slip bands, are at play. The stacking fault energy (SFE) influences the percentage of mechanical twinning, which in turn affects the strain hardening rate.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Hanlin Peng, Siming Huang, Ling Hu, Bingbing Luo, Liejun Li, Ian Baker
Summary: This study explores the weldability, microstructures, and mechanical properties of two L1(2)-nanoparticle-strengthened medium-entropy alloys after electron beam welding (EBW). The results show that strong yet ductile defect-free joints were produced, with larger grain sizes in the fusion zones compared to the heat-affected zones and base materials. Both EBWed MEAs exhibited high yield strengths, high ultimate tensile strengths, and good fracture strains at 77 K. The V-doping improved the cryogenic mechanical properties of the TMT MEA.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Yongxin Wang, Lei Chen, Lizi Shao, Shuo Hao, Motomichi Koyama, Xingzhou Cai, Xiaocong Ma, Miao Jin
Summary: This study investigated the tensile deformation behavior of an Mn-N bearing lean duplex stainless steel with metastable austenite. The results showed that the strain rate had significant influence on the work hardening, strain-induced martensitic transformation, and fracture mechanism.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Jong Woo Won, Seulbi Lee, Hye-Jeong Choe, Yong-Taek Hyun, Dong Won Lee, Jeong Hun Lee
Summary: Cold-rolled pure titanium showed improved sheet formability after undergoing cryogenic-deformation treatment. This treatment increased the thinning capability of the titanium and suppressed cracking during sheet forming. The formation of twins during deformation contributed to high thinning capability and increased strength through grain refinement and dislocation accumulation.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Handong Li, Lin Su, Lijuan Wang, Yanbin Jiang, Jiahui Long, Gaoyong Lin, Zhu Xiao, Yanlin Jia, Zhou Li
Summary: Homogenization heat treatment is a key procedure in controlling the second phase, enhancing composition uniformity, and workability of as-cast Cu-15Ni-8Sn alloy. This study found that electropulsing treatment (EPT) can significantly reduce treatment temperature and time, improve elongation and overall mechanical properties of the alloy.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Yuxuan Wang, Juntao Zou, Lixing Sun, Yunfei Bai, Zhe Zhang, Junsheng Cheng, Lin Shi, Dazhuo Song, Yihui Jiang, Zhiwei Zhang
Summary: A novel mechanical-heat-electricity synergistic method was proposed to enhance the mechanical properties of Cu-15Sn-0.3Ti alloy by forming annealing twins (ATs). The combination method of Rotary swaging (RS) and Electric pulse treatment (EPT) successfully induced recrystallization and refinement of the microstructure, leading to a significant increase in the strength of the alloy within a short time.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Zhiyi Ding, Jiangtao Xie, Tong Wang, Aiying Chen, Bin Gan, Jinchao Song
Summary: This study demonstrated the Ta-induced strengthening of CoCrNi-AlTi MEAs using nanoscale heterogeneous coherent precipitates. The addition of Ta and aging treatments significantly enhanced the mechanical properties of the alloy, including yield strength, ultimate tensile strength, and elongation.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Z. Y. You, Z. Y. Tang, B. Wang, H. W. Zhang, P. Li, L. Zhao, F. B. Chu, H. Ding
Summary: The mechanical properties and microstructural evolution of C-doped TRIP-assisted HEA under dynamic loading conditions were systematically investigated in this study. The results showed that dynamic tensile deformation led to an increase in yield strength and a decrease in ultimate tensile strength, with a trend towards increased total elongation. The primary deformation mechanisms shifted from TRIP and TWIP effects to deformation twinning and dislocations. The presence of carbides formed through C-doping hindered dislocation slip and promoted the activation of multiple twinning systems.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Feng Qin, Feihu Chen, Junhua Hou, Wenjun Lu, Shaohua Chen, Jianjun Li
Summary: Plastic instability in strong multilayered composites is completely suppressed by architecting nanoscale BCC Nb crystalline-amorphous CuNb interfaces.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)