Article
Engineering, Mechanical
M. Homayounfard, M. Ganjiani
Summary: In this paper, a new constitutive model for plastic behavior of metastable austenitic stainless steels at cryogenic temperatures is presented. The model takes into account the dissipative phenomena of strain-induced phase transformation and damage growth during plastic deformation in the framework of continuum damage mechanics. Numerical analysis and experimental verification have shown that the model can accurately predict the hardening behavior, martensite evolution, and damage growth during plastic deformation.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Engineering, Industrial
Qunjie Lu, Jinyang Zheng, Gai Huang, Keming Li, Huiming Ding, Zhenyu Wang, Shaoan Cheng
Summary: The study investigated the cryogenic properties of warm-formed 530408 metastable austenitic stainless steel, showing a decrease in SIM content and dislocation density, as well as an improvement in cryogenic ductility and impact toughness. Despite a decrease in strength, warm-forming can significantly enhance the combined mechanical properties at cryogenic temperatures compared to cold-forming.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2021)
Article
Nanoscience & Nanotechnology
Zongchi Wang, Shouwen Shi, Jingtai Yu, Bingbing Li, Yajing Li, Xu Chen
Summary: A cryogenic cyclic plastic strengthening method is proposed in this paper to improve the yield strength and maintain high elongation by changing the microstructure of the material.
SCRIPTA MATERIALIA
(2023)
Article
Mechanics
P. Fernandez-Pison, J. A. Rodriguez-Martinez, E. Garcia-Tabares, I Aviles-Santillana, S. Sgobba
Summary: This paper characterizes the microstructural evolution, plastic flow, and fracture behaviors of AISI 304L and AISI 316LN stainless steels at extremely low temperatures. It demonstrates that the martensitic transformation in AISI 304L occurs faster and to a greater extent than in AISI 316LN at both 77 K and 4 K. Additionally, experimental results reveal that AISI 316LN displays higher fracture toughness than AISI 304L.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Nanoscience & Nanotechnology
Hua Jiang, Tatsuki Watanabe, Chihiro Watanabe, Norimitsu Koga, Hiromi Miura
Summary: Systematic investigations were conducted on the deformation behavior and microstructure evolution of heterogeneous nanostructured (HNed) SUS316LN austenitic stainless steel at cryogenic temperature (77 K). The HNed steel showed excellent strength/ductility balance due to the high inherent strength of the heterogeneous nanostructure (HN) and significant work hardening caused by transformation-induced plasticity (TRIP). Deformation-induced martensitic transformation (DIMT) occurred in different regions, resulting in different microstructure evolution. Preparing ultrafine HN improved the yield and ultimate strength at cryogenic temperature.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Wangjun Cheng, Dongdong Cui, Yaoning Sun, Wei Liu, Yifei Xu, Bin Liu
Summary: An experimental study was conducted to analyze the undulated work-hardening behavior of S30408 metastable austenitic stainless steel at liquid nitrogen temperature. The effects of cryogenic temperature and deformation degree on the dislocation evolution, phase transformation, slip behavior, and hardening behavior were analyzed. The high strength during cryogenic deformation was mainly attributed to the martensitic transformation and dislocation strengthening.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Coatings & Films
Ali Ghasemi, Seyed Ali Sadough Vanini
Summary: This study investigates the effect of ultrasonic nanocrystal surface modification on the volume fraction of martensite in stainless steel specimens. The results show that the modification at cryogenic temperature leads to higher residual stress but reduced depth of the layer with compressive residual stress. Significant levels of martensite volume fraction are observed on both the surface and subsurface of the modified specimens, with higher hardness at cryogenic temperature.
SURFACE & COATINGS TECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Suning Li, Philip J. Withers, Saurabh Kabra, Kun Yan
Summary: The microstructural evolution and deformation mechanisms of 316L stainless steel were studied at different temperatures using in situ neutron diffraction and transmission electron microscopy (TEM). It was found that the yield strength and ultimate tensile strength of the steel increase significantly at cryogenic temperatures. Deformation-induced martensitic transformation occurs at all cryogenic temperatures, accompanied by the appearance of e-martensite as an intermediate phase. The evolution of lattice strain, phase volume fraction, stacking fault probability, and stacking fault energy were quantified to investigate the correlation between deformation mechanisms and mechanical behavior.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
J. Tabin, K. Nalepka, J. Kawalko, A. Brodecki, P. Bala, Z. Kowalewski
Summary: A remarkable plastic flow instability is observed during tensile deformation of the commercial 304 stainless-steel sheet at room temperature. The occurrence of plastic flow instability in 304 is dependent on the strain rate and specimen gage length. Moreover, the enhanced strain hardening resulting from deformation-induced martensitic transformation facilitates the orderly propagation of the strain-localized band.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Milad Homayounfard, Mehdi Ganjiani, Farnaz Sasani
Summary: The plastic behavior of metastable austenitic stainless steels is greatly affected by strain-induced martensitic transformation. Experimental analysis and microscopic observations show that the martensite content and damage growth are related to the hardening behavior. Damage initiates with a high rate in early stages of transformation but decreases at higher levels until sudden fracture.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2021)
Article
Chemistry, Physical
Sho Takeda, Yoshikazu Ohara, Tetsuya Uchimoto, Hirotoshi Enoki, Takashi Iijima, Eri Tokuda, Takumi Yamada, Yuzo Nagatomo
Summary: This study investigated the feasibility of fusion sensing of eddy current testing (ECT) and ultrasonic testing (UT) as effective tools to clarify the hydrogen-embrittlement mechanism of austenitic stainless steels. Fatigue testing was conducted on hydrogen-charged and uncharged AISI 304 specimens. The effects of hydrogen exposure on martensitic transformation, crack closure, and crack face morphology were examined using ECT and UT.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Nanoscience & Nanotechnology
Michal Jambor, Tomas Vojtek, Pavel Pokorny, Daniel Koutny, Lubos Nahlik, Pavel Hutar, Miroslav Smid
Summary: In this study, the near-threshold fatigue crack propagation behavior in austenitic stainless steel 304L processed by L-PBF was investigated. The results showed that the orientation of the initial notch did not affect the crack propagation behavior and abnormally low threshold stress intensity factor values were recorded. The unique microstructure produced by L-PBF was found to be the main reason for the absence of crack closure and the low threshold values.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Nanoscience & Nanotechnology
Norimitsu Koga, Tatsuya Nameki, Osamu Umezawa, Valentin Tschan, Klaus-Peter Weiss
Summary: The study demonstrates that the tensile properties of commercial ferrite and austenite duplex stainless steel improve at lower temperatures, except at 40K. The steel exhibits high elongation at 8K compared to other test temperatures, due to the occurrence of serration which increases the volume fraction of deformation induced martensite.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Wei Liu, Nan Wang, Yongnan Chen, Zhimin Hou, Qinyang Zhao, Wenbo Ouyang, Yan Kang, Gang Wu, Lixia Zhu, Yongqing Zhao
Summary: This paper investigates the damping performance of typical titanium alloys at cryogenic temperatures using micro harmonic vibration. The effects of vibration modulus at different frequencies are analyzed, and the crack propagation mechanism is discussed. The increase of internal dislocations improves damping performance and leads to interface cracking, which is correlated with frequency. The aggregation of dislocations at the interface causes interface cracks and transgranular fractures in the b phase, while dislocations in the a phase activate and glide toward the boundary, resulting in intergranular fractures. The crack propagation of the a phase exhibits hysteresis behavior compared to the b phase during harmonic vibration. At -60°C with 200 Hz, the deflected second crack tip of the beta phase consumes higher harmonic vibration energy, slowing down the crack growth rate and reaching peak damping performance. The study provides experimental data and theoretical support for the vibration damping behavior of typical titanium alloys at cryogenic temperature.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Materials Science, Multidisciplinary
M. Kreins, J. Wilkes, S. Wesselmecking, U. Krupp
Summary: The Bauschinger effect in austenitic-ferritic duplex stainless steel 1.4462 was investigated, and it was found that alpha ' precipitates formed in the ferritic phase significantly enhance the Bauschinger effect, contrary to the general belief. The presence of these precipitates increases the phase difference between austenite and ferrite, leading to enhanced deformation incompatibility and local dislocation density gradients. Despite their small size and coherence, the alpha ' precipitates generate long-range back stresses that contribute to the Bauschinger effect.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2022)
Article
Health Care Sciences & Services
Kyoungjune Pak, Sae-Ock Oh, Tae Sik Goh, Hye Jin Heo, Myoung-Eun Han, Dae Cheon Jeong, Chi-Seung Lee, Hokeun Sun, Junho Kang, Suji Choi, Soohwan Lee, Eun Jung Kwon, Ji Wan Kang, Yun Hak Kim
JOURNAL OF MEDICAL INTERNET RESEARCH
(2020)
Article
Materials Science, Multidisciplinary
Tae-Rim Kim, Chi-Seung Lee
KOREAN JOURNAL OF METALS AND MATERIALS
(2020)
Article
Multidisciplinary Sciences
Beop-Yong Lim, Youngwoong Kim, I Hoseok, Chi-Seung Lee
SCIENTIFIC REPORTS
(2020)
Letter
Surgery
Na Hyeon Lee, Hyo Yeong Ahn, Chi-Seung Lee
ASIAN JOURNAL OF SURGERY
(2020)
Article
Chemistry, Multidisciplinary
Eunji Kim, Chi-Seung Lee, Jeong Su Cho, I Hoseok, Yeong Dae Kim, Eunsoo Kim, Hyo Yeong Ahn
Summary: The study demonstrates that video-assisted thoracic surgery (VATS) under local anesthesia shows better clinical outcomes and lower postoperative recurrence rates compared to general anesthesia in patients with primary spontaneous pneumothorax (PSP).
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Ji-Hun You, Chung Won Lee, Up Huh, Chi-Seung Lee, Dongman Ryu
Summary: This study investigated the correlation between peak wall stress (PWS) and abdominal aortic aneurysm (AAA) geometry through computational simulations, using the Holzapfel model and varying orientations of collagen fibers and thicknesses of aortic layers. Material constants were estimated from biaxial tensile test results of normal abdominal aorta and AAA. Geometric factors such as aneurysm diameter, height, neck angle, and iliac angle were identified as factors affecting AAA rupture, with a simulation scenario created based on computed tomography data of AAA patients to estimate the correlation between PWS and AAA geometry.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Cheol-Jeong Kim, Seung Min Son, Sung Hoon Choi, Tae Sik Goh, Jung Sub Lee, Chi-Seung Lee
Summary: This study analyzed spinal stability and safety after posterior spinal fusion with different fixation methods and screw types in patients with osteoporotic thoracolumbar burst fractures. It found that the T10-T11-L1-L2 model had the lowest ROM and stress levels.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Chan-Hee Song, Jun-Sung Park, Byung-Wan Choi, Jung Sub Lee, Chi-Seung Lee
Summary: The study found that an increasing porosity of spinal implants led to increased range of motion, decreased equivalent stress on adjacent intervertebral discs, adjacent bone stress on pedicle screw and spinal cage. However, as the porosity decreased, the safety factor showed a rapid decrease.
APPLIED SCIENCES-BASEL
(2021)
Article
Materials Science, Multidisciplinary
Dongman Ryu, Up Huh, Seungik Baek, Il Jae Wang, Chi-Seung Lee
Summary: The study revealed that the inflation time of REBOA affects the properties of organ tissues, and characterization of the mechanical behavior and clinical examination of organ tissues should be based on the operation time. The results demonstrated that even in ischemic tissues, the characteristic of soft tissues is maintained with loading rate.
MATERIALS & DESIGN
(2021)
Article
Engineering, Mechanical
Byeong-Cheol Jeong, Jungyul Park, Chi-Seung Lee, Dongman Ryu
Summary: This study proposed a computational simulation technique for the hypertrophy of the inferior rectus muscle, examined the behavior of the muscle and eye movement under different loading conditions, and suggested optimal loading conditions for simulation. Supplementary data for the selection of surgical location and range were also provided.
TRANSACTIONS OF THE KOREAN SOCIETY OF MECHANICAL ENGINEERS B
(2021)
Article
Materials Science, Multidisciplinary
Tae-Rim Kim, Hyo Yeong Ahn, Yun Hak Kim, Seog-Young Yoon, Chi-Seung Lee
Summary: This study investigated the nonlinear behavior of polyurethane foam (PUF) under various conditions. A elastoviscoplastic constitutive model was adopted and discretized using an implicit time integration algorithm in ABAQUS. Parameter determination method was used to identify material parameters, allowing for the prediction of PUF's macroscopic material response.
MECHANICS OF MATERIALS
(2021)
Article
Engineering, Biomedical
Byeong-Jun Kim, Hyo Yeong Ahn, Chanhee Song, Dongman Ryu, Tae Sik Goh, Jung Sub Lee, Chiseung Lee
Summary: In this study, a novel computer modeling and simulation technique was proposed for tracking lung bronchi (or tumors) during respiration. Patient-specific finite element models were created using CT scans and Ogden's hyperelastic model was used to describe the material behavior of the lung. The simulation results were compared to clinical data to validate the technique. The study provides a step-by-step framework for modeling the respiratory system and tracking bronchi motion, and considers various organs and their impact on lung motion during respiration.
PHYSICAL AND ENGINEERING SCIENCES IN MEDICINE
(2023)
Article
Engineering, Biomedical
Beop-Yong Lim, Dongman Ryu, I Hoseok, Chiseung Lee
Summary: The purpose of this study is to propose a new in silico Nuss procedure that can predict the outcomes of chest wall deformity correction. A 3D geometric and finite element model of the chest wall was built from a CT image of a 15-year-old male patient with mild pectus excavatum. Simulations of anterior translating the metal bar and maintaining equilibrium after a 180-degree rotation were performed. A simulation with the chest wall finite element model and intercostal muscles was also conducted. The results of the REM simulation were found to be most similar to the actual patient's outcomes. By comparing clinical and mechanical indicators with postoperative patients, the authors conclude that the REM simulation of the in silico Nuss procedure proposed in this study best simulates the actual surgery.
PHYSICAL AND ENGINEERING SCIENCES IN MEDICINE
(2023)
Article
Biotechnology & Applied Microbiology
On Sim, Dongman Ryu, Junghwan Lee, Chiseung Lee
Summary: Most studies on OPLL ossification using the finite element method have been conducted in the neutral state, which does not reflect the actual behavior of the cervical spine. This study conducted a biomechanical analysis during flexion and extension behaviors and found that spinal cord decompression did not work well in these movements. Therefore, additional surgery using an anterior approach should be considered for patients with focal OPLL who require posterior decompression.
BIOENGINEERING-BASEL
(2022)
Article
Engineering, Mechanical
Dongman Ryu, Seunghwan Song, Chi-Seung Lee
Summary: This study examined the tensile behaviors of suture materials for cardiac surgical purposes based on strain rates, conducted uniaxial tensile tests, and compared results with previous studies. The mechanical behaviors and properties of the sutures were measured, providing insights for future research in this understudied area.
TRANSACTIONS OF THE KOREAN SOCIETY OF MECHANICAL ENGINEERS B
(2021)
