Updated on 2024/05/14

 
KOMODA Ryosuke
 
Scopus Paper Info  
Total Paper Count: 0  Total Citation Count: 0  h-index: 8

Citation count denotes the number of citations in papers published for a particular year.

Affiliation
Faculty of Engineering Department of Mechanical and Control Engineering
Job
Associate Professor
External link

Research Interests

  • Fretting Fatigue

  • Metal Fatigue

  • Hydrogen Embrittlement

Research Areas

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Mechanics of materials and materials  / Hydrogen Embrittlement

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Mechanics of materials and materials  / Metal Fatigue

Biography in Kyutech

  • 2023.01
     

    Kyushu Institute of Technology   Faculty of Engineering   Department of Mechanical and Control Engineering   Associate Professor  

Biography before Kyutech

  • 2018.10 - 2022.12   Fukuoka University   Assistant Professor   Japan

Academic Society Memberships

Papers

  • Improvement of fretting fatigue strength by carbon monoxide and catalyst activation under chemomechanical effects of fretting Reviewed International journal

    Masanobu Kubota, Ryosuke Komoda, Yuki Nakamura

    Theoretical and Applied Fracture Mechanics ( ELSEVIER )   121   103460 - 103466   2022.06

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    It is known that the fretting fatigue strength in hydrogen (H2) gas is lower than that in air. The objective of this study is to mitigate the hydrogen effect during the fretting fatigue test in H2 gas by adding carbon monoxide (CO) to the H2 environment. The expected CO effect was reduction in the hydrogen uptake into the material following deactivation of the catalytic surface where H2 molecules dissociate into H atoms. However, an unexpected result, which was unique in fretting, was obtained. The fretting fatigue test using JIS SUS304 austenitic stainless steel was performed in H2, argon (Ar), 2 vol% CO mixed H2, and 2 vol% CO mixed Ar gases. The fretting fatigue strengths in the CO-mixed gases were significantly improved. For instance, the fretting fatigue life at σa = 240 MPa was 8.8 × 105 cycles in the H2 and 107 cycles or longer in the CO mixed H2. The cause of the improved fretting fatigue strength was the formation of amorphous carbon between the contacting surfaces during the fretting. The carbon reduced the tangential force coefficient between the contacting surfaces from around 0.6 in the H2 to 0.2 or less in the CO mixed H2. The reduced tangential force resulted in improvement of the fretting fatigue strength. Although the detailed mechanisms of the carbon deposition were unclear, it is plausible that the catalytic action of the metal surface for the CO decomposition into C and O was activated by the effect of fretting, such as removal of the surface oxide layer and other chemomechanical effects.

    DOI: 10.1016/j.tafmec.2022.103460

  • Ammonia mitigation and induction effects on hydrogen environment embrittlement of SCM440 low-alloy steel Reviewed International journal

    Nang Zhang, Ryosuke Komoda, Kazuki Yamada, Masanobu Kubota, Aleksandar Staykov

    International Journal of Hydrogen Energy ( Elsevier )   47 ( 33 )   15084 - 15093   2022.04

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    The effect of ammonia (NH3) contained in hydrogen (H2) gas on hydrogen environment embrittlement (HEE) of SCM440 low-alloy steel was studied in association with the NH3 concentration, loading rate, and gas pressure. NH3 worked as both mitigator of the HEE and inducer of hydrogen embrittlement (HE) depending on the testing conditions. The mitigation of the HEE was achieved by the deactivation of the iron (Fe) surface for H2 dissociation caused by the preferential adsorption of NH3 on the Fe surface, which is enhanced by the increase in the NH3 concentration and decrease in the H2 gas pressure. NH3 induced HE was caused due to creating hydrogen by the NH3 decomposition. Since the NH3 decomposition rate is low, the induction effect was observed when the loading rate was low. The effect of NH3 was determined by the competition of the mitigation and induction effects.
    © 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

  • Effect of gas pressure on hydrogen environment embrittlement of carbon steel A106 in carbon monoxide mixed hydrogen gas Reviewed International journal

    Ryosuke Komoda, Masanobu Kubota, Aleksandar Staykov, Patrick Ginet, Francoise Barbier, Jader Furtado, Laurent Prost, Akihide Nagao

    Metallurgical and Materials Transactions A,   53   74 - 85   2021.11

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    The addition of a small volume fraction of carbon monoxide (CO) gas to pure gaseous H2 potentially mitigates the susceptibility of steel to hydrogen environment embrittlement (HEE). The effect of environmental gas pressure on the mitigation of HEEs by a mixture of H2 and CO was examined in this study. Fracture toughness tests of an ASTM A106 pipe carbon steel were carried out in H2 gas containing CO. The environmental gas pressures at which the fracture toughness tests were conducted were 0.6, 1.0 and 4.0 MPa. The addition of a certain concentration of CO to H2 gas completely prevented HEE. The CO concentration achieving complete HEE prevention increased with an enhancement of the environmental gas pressure. Molecular dynamics (MD) simulations were further conducted to interpret the experimental results based on the interactions ofH2 and CO with the Fe surface in conjunction with the effect of gas pressure. The MD simulations revealed that the dissociation rate of dihydrogen molecules to atomic hydrogen on the Fe surface significantly increased with an elevation of the gas pressure, whereas the adsorption rate of CO on the Fe surface was almost independent of the gas pressure. These results suggest that the increase in the gas pressure relatively promotes hydrogen uptake into the material in the presence of CO, which accounts for the experimental results showing that the CO concentration achieving complete HEE prevention increased with the elevation of the gas pressure.

  • Effect of hydrogen on creep properties of SUS304 austenitic stainless steel Reviewed International journal

    Daisuke Takazaki, Toshihiro Tsuchiyama, Ryosuke Komoda, Mohsen Dadfarnia, Brian Somerday, Petros Sofronis, Masanobu Kubota

    Corrosion   77 ( 3 )   256 - 265   2020.11

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    The objective of this study is to derive mechanistic insight into the degradation of metals in high-temperature hydrogen in order to enable the safety of evolving hydrogen technologies that operate at elevated temperature. Creep testing was performed in argon and hydrogen gases under absolute pressure of 0.12 MPa at 873 K. The material was JIS SUS304 austenitic stainless steel. Results revealed that the creep life (time to failure) and creep ductility (strain to failure) of the SUS304 in hydrogen gas and in argon displayed opposite trends. While the creep life (time to failure) of the SUS304 in hydrogen gas was significantly shorter than that in argon, creep ductility (strain to failure) was higher in hydrogen. Associated with the relatively higher creep ductility, evidence of transgranular micro void coalescence was more prevalent on fracture surfaces produced in hydrogen compared to those produced in argon. In addition, analysis of the steady-state creep relationships in hydrogen and argon indicated that the same creep mechanism operated in the two environments, which was deduced as dislocation creep. Regarding the mechanisms governing reduced creep life in hydrogen, the effects of decarburization, carbide formation, and the hydrogen enhanced localized plasticity mechanism were investigated. It was confirmed that these effects were not responsible for the reduced creep life in hydrogen, at least within the creep life range of this study. Alternately, the plausible role of hydrogen was to enhance the vacancy density, which led to magnified lattice diffusion (self-diffusion) and associated dislocation climb. As a consequence, hydrogen accelerated the creep strain rate and shortened the creep life.

    DOI: 10.5006/3678

  • Coadsorption of CO and H2 on an iron surface and its implication on the hydrogen embrittlement of iron Reviewed International journal

    Aleksandar Staykov, Ryosuke Komoda, Masanobu Kubota, Patrick Ginet, Francoise Barbier, Jader Furtado

    The Journal of Physical Chemistry C ( ACS Publications )   123 ( 50 )   30265 - 30273   2019.11

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    We investigated the competitive coadsorption of carbon monoxide and hydrogen gas on an iron surface with a 110 facet using density functional theory. Our study discusses the hydrogen dissociation reaction on a fresh iron surface and a surface with varying carbon monoxide coverage. Additionally, we investigated the carbon monoxide surface adsorption as a function of the carbon monoxide surface coverage. Our results show different trends for the carbon monoxide adsorption and hydrogen dissociation on surfaces with low and high CO coverage. Those opposite trends were related to the charge of the surface iron atoms and the available surface electron density which is necessary to facilitate the carbon monoxide adsorption and catalyze the hydrogen dissociation reaction. The subsurface diffusion of predissociated surface hydrogen atoms has been included in the model. It was found that the atomistic hydrogen diffusion into the material is also related to the carbon monoxide surface coverage. Our theoretical results confirmed that a small amount of carbon monoxide as an impurity in the hydrogen gas can mitigate the effect of hydrogen embrittlement by significantly reducing the rate of hydrogen dissociation on the iron surface and thus reduce the hydrogen uptake into the bulk of the material. To verify the theoretical results, we carried out a fracture toughness test of pure iron in a high-purity H2, CO and H2 mixture, and N2 gases. This material suffered from hydrogen embrittlement, in other words, reduction in the fracture toughness due to hydrogen. We could derive the complex dependence on the hydrogen embrittlement manifestation as a function of the H2/CO gas mixture ratio and gas exposure time.

    DOI: 10.1021/acs.jpcc.9b06927

  • The inhibitory effect of carbon monoxide contained in hydrogen gas environment on hydrogen-accelerated fatigue crack growth and its loading frequency dependency Reviewed International journal

    Ryosuke Komoda, Kazuki Yamada, Masanobu Kubota, Patrick Ginet, Francoise Barbier, Jader Furtado, Laurent Prost

    International Journal of Hydrogen Energy ( ELSEVIER )   44 ( 54 )   29007 - 29016   2019.11

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    The effect of carbon monoxide (CO) contained in H2 gas as an impurity on the hydrogen-accelerated fatigue crack growth of A333 pipe steel was studied in association with loading frequency dependency. The addition of CO to H2 gas inhibited the accelerated fatigue crack growth due to the hydrogen. The inhibitory effect was affected by the CO content in the H2 gas, loading frequency, and crack growth rate. Based on these results, it was revealed that the inhibitory effect of CO was governed by both competition between the rate of fresh surface creation by the crack growth and the rate of coverage of the surface by CO and time for hydrogen diffusion in the material to the crack tip with reduced hydrogen entry by CO.

    DOI: 10.1016/j.ijhydene.2019.09.146

  • Effects of hydrogen and weld defect on tensile properties of SUH660 and SUS316L welded joints Invited Reviewed International journal

    Masanobu Kubota, Ryosuke Komoda, Xuesong Cui, Hiroshi Wakabayashi, Yasuhisa Tanaka

    International Journal of Mechanical Engineering and Robotics Research   8 ( 5 )   713 - 718   2019.09

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    The effect of hydrogen on the tensile properties of the SUH660 and SUS316L different materials welded joints was characterized in conjunction with the joint shape and weld defects. The butt welded joint specimen without weld defect fractured at the SUS316L base material, and did not cause hydrogen embrittlement (HE). However, the failure position of the spigot-lap welded joint specimen moved from the SUS316L base material to the weld part when hydrogen charging was applied. This resulted in a significant reduction of the elongation. It was presumed that the HE was induced by the stress concentration due to the weld shape. The weld defect induced HE in both joints. The weld defect was produced by incomplete penetration. It also caused incomplete mixing of the weld metal. Consequently, filler nickel segregated around the weld defect, then HE occurred.

    DOI: 10.18178/ijmerr.8.5.713-718

  • Inhibitory effect of oxygen on hydrogen-induced fracture of A333 pipe steel Reviewed International journal

    Ryosuke Komoda, Masanobu Kubota, Aleksandar Staykov, Patrick Ginet, Francoise Barbier, Jader Furtado

    Fatigue & Fracture of Engineering Materials & Structures   42 ( 6 )   1387 - 1401   2019.06

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    The effect of oxygen contained in hydrogen gas environment as an impurity on hydrogen environment embrittlement (HEE) of A333 pipe steel was studied through the fracture toughness tests in hydrogen gases. The oxygen contents in the hydrogen gases were 100, 10, and 0.1 vppm. A significant reduction in the J‐Δa curve was observed in the hydrogen with 0.1‐vppm oxygen. Under given loading conditions, the embrittling effect of hydrogen was completely inhibited by 100 vppm of oxygen. In the case of the hydrogen with 10‐vppm oxygen, initially the embrittling effect of hydrogen was fully inhibited, and then subsequently appeared. It was confirmed that 1‐vppm oxygen reduced the embrittling effect of hydrogen. The results can be explained by the predictive model of HEE proposed by Somerday et al.

    DOI: 10.1111/ffe.12994

  • Effect of contact pressure on fretting fatigue failure of oil-well pipe material Invited Reviewed International journal

    Daisuke Takazaki, Masanobu Kubota, Ryosuke Komoda, Yosuke Oku, Taizo Makino and Masaaki Sugino

    International Journal of Fatigue,   101 ( 1 )   67 - 74   2017.08

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    As the result of a full-scale test of a thread joint connecting oil-well casing pipes, fretting fatigue failure at the middle of the thread engagement part was identified. The objective of this study is to understand the mechanism of the fretting fatigue failure at the middle of the contact part. A similar failure mode was reproduced by a bridge-pad type fretting fatigue test under gross slip conditions. It was found that the crack position moved from the contact edge toward the inside of the contact part with the progress of the fretting wear.

    DOI: 10.1016/j.ijfatigue.2017.03.024

  • Fretting fatigue on thread root of premium threaded connections Invited Reviewed International journal

    Yosuke Oku, Masaaki Sugino, Yoshinori Ando, Taizo Makino, Ryosuke Komoda, Daisuke Takazaki and Masanobu Kubota

    Tribology International   108   111 - 120   2017.04

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    Identification of the fatigue failure mode of the premium threaded connection for Oil Country Tubular Goods pipes was conducted via full-scale fatigue tests. A through-wall crack was found at the imperfect thread root of the male embodiment, but the crack initiation site depended on the stress level. At relatively higher stress amplitude region, the crack originated from the thread rounded corner by stress concentration. At relatively lower stress amplitude region, the crack originated at the middle of the thread root because of fretting fatigue. To investigate the fretting fatigue mechanism in the threaded connection, a fundamental fretting fatigue test was conducted. This test achieved the fretting fatigue failure at the middle of the contact surface under large gross slip condition.

    DOI: 10.1016/j.triboint.2016.10.021

  • Effect of addition of oxygen and water vapor on fretting fatigue properties of an austenitic stainless steel in hydrogen Reviewed International journal

    Ryosuke Komoda, Masanobu Kubota and Jader Furtado

    International Journal of Hydrogen Energy   40 ( 21 )   16868 - 16877   2015.12

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    JIS SUS304 fretting fatigue test was done in high-purity hydrogen, an oxygen-hydrogen mixture and humidified hydrogen. The fretting fatigue strength in hydrogen was drastically changed depending on the oxygen level. Based on the XPS (X-ray photoelectron spectroscopy) analysis of the fretted surface, it was found that the fretting removed the original protection layer of the stainless steel, however, the addition of water vapor or ppm-level of oxygen produced an oxide layer on the fretted surface during the fretting that surpassed the removal effect of the initial oxide layer by fretting. In fact, a strong adhesion between the contacting surfaces occurred and no fretting wear particles were observed in the high-purity hydrogen. On the other hand, oxidized fretting wear particles were found in the oxygen-hydrogen mixture. Based on the geometry of contact used in this study, a severe concentration of the contact pressure arouse at the contact edge. This produces a compressive stress field in the specimen where the crack growth was suppressed. This stress concentration was relieved when fretting wear occurs. Therefore, the change in the fretting fatigue strength in hydrogen by the addition of oxygen is closely related to the change in the wear behavior.

    DOI: 10.1016/j.ijhydene.2014.12.129

  • Effect of oxygen addition on fretting fatigue strength in hydrogen of JIS SUS304 stainless steel Invited Reviewed International journal

    Ryosuke Komoda, Masanobu Kubota, Yoshiyuki Kondo and Jader Furtado

    Tribology International   76   92 - 99   2014.08

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    Fretting fatigue test of SUS304 austenitic stainless steel was performed in air, in hydrogen gas, and in oxygen–hydrogen mixture. The fretting fatigue strength is more significantly reduced in hydrogen as compared to air. An increase in the fretting fatigue strength was found in the mixture. The mechanisms were investigated focusing on crack initiation. As the result, the crack initiation limit was significantly lower in hydrogen than in air, and increased in the mixture. The tangential force coefficient in the mixture is similar to that in air. The morphology of the fretting damage in the mixture was similar to that in air. These results indicated that the adhesion between contacting surfaces was prevented by addition of oxygen.

    DOI: 10.1016/j.triboint.2014.02.025

  • Reduction in fretting fatigue strength of austenitic stainless steels due to internal hydrogen Invited Reviewed International journal

    Ryosuke Komoda, Naoto Yoshigai, Masanobu Kubota and Jader Furtado

    Advanced Materials Research   891-892   891 - 896   2014.03

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    Fretting fatigue is one of the major factors in the design of hydrogen equipment. The effect of internal hydrogen on the fretting fatigue strength of austenitic stainless steels was studied. The internal hydrogen reduced the fretting fatigue strength. The reduction in the fretting fatigue strength became more significant with an increase in the hydrogen content. The reason for this reduction is that the internal hydrogen assisted the crack initiation. When the fretting fatigue test of the hydrogen-charged material was carried out in hydrogen gas, the fretting fatigue strength was the lowest. Internal hydrogen and gaseous hydrogen synergistically induced the reduction in the fretting fatigue strength of the austenitic stainless steels. In the gaseous hydrogen, fretting creates adhesion between contacting surfaces where severe plastic deformation occurs. The internal hydrogen is activated at the adhered part by the plastic deformation which results in further reduction of the crack initiation limit.

    DOI: 10.4028/www.scientific.net/AMR.891-892.891

  • Fundamental Mechanisms Causing Reduction in Fretting Fatigue Strength by Hydrogen (Effect of Hydrogen on Small Crack Initiation at the Adhered Spot) Reviewed

    Ryosuke Komoda, Masanobu Kubota, Yoshiyuki Kondo and Jader Furtado

    Transaction of the Japan Society of Mechanical Engineers, Series A   79 ( 801 )   536 - 545   2013.05

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    The authors have reported a significant reduction in fretting fatigue strength of austenitic stainless steels due to hydrogen. One of the causes of the reduced fretting fatigue strength in hydrogen is adhesion between contacting surfaces and following formation of small cracks which emanate from the adhered spots. The objective of this study is to understand the effect of hydrogen on the initiation of the small cracks under fretting fatigue conditions. Since the adhesion between contacting surfaces during fretting in hydrogen is very localized, a small contact length was used in this test in order to facilitate understanding by avoiding such localization. The fretting fatigue test of an austenitic stainless steel SUS304 was performed in air and 0.13MPa hydrogen. In the fretting fatigue test, hydrogen participates in the initiation of the fretting fatigue crack. It can be presumed that high strain at the contact edge activates hydrogen assisted fracture in terms of dislocation mobility. Adhesion mimic test, in which a small contact area was welded, was also performed. As the result, the crack initiation limit evaluated by the maximum range of shear stress was significantly lower in hydrogen than in air. Hydrogen assists small crack initiation under fretting fatigue conditions. This is one of the possible causes of the significant reduction of fretting fatigue strength in hydrogen.

    DOI: 10.1299/kikaia.79.536

  • Effect of alloy composition on CO mitigation effect on gaseous hydrogen embrittlement of ferritic steel Reviewed International journal

    Nan Zhang, Ryosuke Komoda, Masanobu KUbota, Aleksandar Staykov

    Proceeding of the Thirty-third (2023) International Ocean and Polar Engineering Conference   3139 - 3144   2023.06

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    Cnada   Ottawa   2023.06.18  -  2023.06.23

  • Effect of hydrogen on creep properties of SUY-1 industrial pure iron Reviewed International journal

    Kentaro Wada, Toru Yamashita, Daisuke Takazaki, Ryosuke Komoda, Masanobu Kubota

    Proceedings of JSME International Conference on Matarials and Processing 2022   2022.11

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    The objective of this study is to gain a better understanding of the hydrogen effect on the creep properties in order to establish the science enables to secure the safety of advanced high-temperature hydrogen technologies. Creep testing was carried out in argon and hydrogen gases at 873 K. The absolute gas pressure at which the creep tests were performed was 0.12 MPa. The material was JIS SUY-1 industrial pure iron. It was used as a model material having a BCC crystalline structure. A pure single-phase microstructure may be beneficial to elucidate the central role of hydrogen in the creep deformation in the presence of hydrogen. Hydrogen accelerated the creep strain rate resulting in significant reduction in the creep life. Based on the creep deformation mechanism map by Frost and Ashby, the creep in this experiment was driven by a power-law creep. The specimens formed a double cup fracture and exhibited a dimple fracture surface regardless of the environment and creep life. There was no significant difference in the fracture profile and fracture surface morphology. These observations indicated no change in the creep deformation mechanism in hydrogen. This was similar to the creep of SUS304 stainless steel in hydrogen. A similar mechanism that hydrogen may enhance the vacancy density, which led to a magnified lattice diffusion and associated dislocation climb, may be adopted.

  • Effect of hydrogen on fatigue crack growth behavior of low alloy steels in methane Reviewed International journal

    Shunsuke Umezaki, Masanobu Kubota, Ryosuke Komoda, Naho Inoue, Hiroshi Okano, Tomoharu Ishida, Shusaku Takagi

    Proceedings of JSME International Conference on Matarials and Processing 2022   2022.11

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    The utilization of hydrogen is one of the keys to achieving sustainable development goals. During the transition toward a hydrogen society, the repurposing of existing non-hydrogen energy systems to a hydrogen one is very important in terms of costs and smooth reforming of energy and industrial structures. In this context, the mixing of hydrogen with natural gas can be one of the important technologies. In this study, fatigue crack growth testing was carried out in air, hydrogen, methane / hydrogen mixed gases in order to characterize the effect of hydrogen on the fatigue crack growth behavior in natural gas. The test material was JIS SCM435 low alloy steel. Two materials, which have different strength levels, were used. Both materials showed acceleration of the fatigue crack growth rate in only hydrogen and the mixed gases. The extent of the acceleration was less in the mixed gas compared with that in hydrogen. It is presumed that the hydrogen effect was less pronounced by the reduced partial hydrogen pressure in the mixed gas. Also, the extent of the acceleration was less in the lower strength material than in the higher strength one. It was confirmed that methane had no detrimental effect on the fatigue crack growth behavior of both materials.

  • Mitigation of hydrogen environment embrittlement of carbon steels A106 and A333 by addition of CO to H2 gas and its gas pressure dependence International journal

    Ryosuke Komoda, Masanobu Kubota, Aleksandar Staykov, Patrick Ginet, Francoise Barbier, Jader Furtado, Laurent Prost, Akihide Nagao

    Proceedings of the Fourth International Conference on Metals & Hydrogen   2022.10

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    The addition of carbon monoxide (CO) to hydrogen (H2) gas can mitigate the hydrogen environment embrittlement (HEE) of steels. The effect of gas pressure on the mitigation of the HEE of low carbon steels by the addition of CO was investigated in this study by a concerted effort of fracture toughness tests in H2 gas containing CO and molecular dynamics (MD) simulations of the surface chemical reactions of H2 and CO with the iron (Fe) surface. The degree of mitigation of the HEE depended on the gas pressure and CO concentration; the CO concentration to achieve complete HEE prevention was enhanced with an increase in the gas pressure, in other words, the CO mitigation effect was reduced by the increased gas pressure. The MD simulations revealed that the dissociation rate of dihydrogen molecules to atomic hydrogen on the Fe surface was significantly enhanced with an increase in the gas pressure, whereas the adsorption rate of CO on the Fe surface was almost independent of the gas pressure. These simulation results suggest that the hydrogen uptake into a steel is more effectively prohibited in a lower pressure H2 gas containing CO, which accounts for the gas pressure dependence of the CO mitigation effect observed in the fracture toughness tests.

  • Mitigation of hydrogen embrittlement by addition of gas impurities to hydrogne gas Invited

    Ryosuke Komoda

    Journal of The Japan Research Institute for Screw Threads and Fasteners   53 ( 7 )   212 - 225   2022.07

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  • Loading dependence of mitigation effect of CO on hydrogen embrittlement of pure iron and low carbon steel Reviewed International journal

    Ryosuke Komoda, Masanobu Kubota, Aleksandar Staykov, Patrick Ginet, Jader Furtado, Laurent Prost, Akihide Nagao

    Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference   3038 - 3043   2022.06

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    The mitigation effect of carbon monoxide (CO) on hydrogen embrittlement (HE) was studied in terms of the loading rate dependence by fracture toughness tests, fatigue crack growth tests, and density functional theory (DFT) simulations. The experimental results demonstrated that the mitigation effect is reduced with a decreasing loading rate in the lower crack growth rate region. The DFT simulations revealed that this is caused by the incomplete coverage of the iron surface by CO. Oppositely, the mitigation effect increased with the decreasing loading rate in the higher crack growth rate region due to a lack of CO adsorption on the iron surface.

  • Achieving a carbon neutral future through advanced functional materials and technologies Invited Reviewed International journal

    Andrew Chapman, Elif Ertekin, Masanobu Kubota, Akihide Nagao, Kaila Bertsch, Arnaud Macadre, Toshihiro Tsuchiyama, Takuro Masamura, Setsuo Takaki, Ryosuke Komoda, Mohsen Dadfarnia, Brian Somerday, Alexander Staykov, Joichi Sugimura, Yoshinori Sawae, Takehiro Morita, Hiroyoshi Tanaka, Kazuyuki Yagi, Vlad Niste, Prabakaran Saravanan, Shogo Onitsuka, Ki-Seok Yoon, Seiji Ogo, Toshinori Matsushima, Ganbaatar Tumen-Ulziil, Dino Klotz, Dinh Hoa Nguyen, George Harrington, Chihaya Adachi, Hiroshige Matsumoto, Leonard Kwati, Yukina Takahashi, Nuttavut Kosem, Tatsumi Ishihara, Miho Yamauchi, Bidyut Baran Saha, Md. Amirul Islam, Jin Miyawaki, Harish Sivasankaran, Masamichi Kohno, Shigenori Fujikawa, Roman Selyanchyn, Takeshi Tsuji, Yukihiro Higashi, Reiner Kirchheim, Petros Sofronis

    Bulletin of the Chemical Society of Japan   59 ( 1 )   73 - 103   2022.01

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    The recently released 6th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) makes it clear that keeping global temperature rise below 1.5 degrees will require the world to achieve carbon-neutrality by 2050. Meeting this decarbonization challenge requires rapid and sustained innovations in materials science and engineering, with a focus on accelerating technology which will enable the realization of a carbon neutral energy system. This study details the broad, yet targeted research themes being pioneered within the International Institute for Carbon-Neutral Energy Research (I2CNER). These approaches include hydrogen materials compatibility, novel catalysis concepts anchored on bio-mimetic activation of small molecules, promising materials for efficient and durable fuel and solar cells, nanostructure-based thermal energy storage, nanomembranes and technology for direct air capture of CO2, geomaterials and devices for carbon storage, and next generation nonflammable refrigerants. We outline the state of the art for this suite of materials and technologies and detail the impact of their deployment on reducing the CO2 emissions of Japan by 2050. More specifically, approximately 0.46% of the total required CO2 reductions can be realized by I2CNER’s current innovations if they are applied to appropriate energy systems. This study represents a solid outcome of interdisciplinary, international collaboration.

  • Effect of ammonia impurity on hydrogen embrittlement of SCM440 low-alloy steel in hydrogen gas Reviewed International journal

    Zhang Nan, Ryosuke Komoda, Kazuki Yamada, Cynthia Volkert, Lin Tian, Reiner Kirchheim, Petros Sofronis, Hosseinisarani Zahra S, Mohsen

    Proceeding of the Thirtieth (2020) International Ocean and Polar Engineering Conference   3030 - 3035   2020.10

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    Ammonia (NH3) was added to hydrogen gas as an impurity, then hydrogen embrittlement (HE) of the SCM440 low-alloy steel was investigated by fracture toughness tests. NH3 showed inhibition of the HE when the loading rate was relatively high. However, the inhibitory effect decreased with the decrease in the loading rate, as well as with an increase in the gas pressure. It was found that NH3 acted as both an inhibitor of the HE and a cause of the HE depending on the loading rate and gas pressure.

  • Effect of hydrogen on fatigue limit of SCM435 low-alloy steel Reviewed International journal

    Masanobu Kubota, Mio Fukuda, Ryosuke Komoda

    Procedia Structural Integrity ( ELSEVIER )   19   520 - 527   2019.12

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    The objective of this study is to gain a basic understanding of the effect of hydrogen on the fatigue limit. The material was a low-alloy steel modified to be sensitive to hydrogen embrittlement by heat treatment. A statistical fatigue test was carried out using smooth and deep-notched specimens at a loading frequency of 20 Hz. The environment was laboratory air and hydrogen gas. The hydrogen gas pressure was 0.1 MPa in gauge pressure. The fatigue limit of the smooth specimen was higher in the hydrogen gas than that in air, although the material showed severe hydrogen embrittlement during the SSRT (Slow Strain Rate Test). The fatigue limit of the deep-notched specimen in the hydrogen gas was the same as that in air. For the smooth specimen, the fatigue limit was determined by whether or not a crack was initiated. For the deep-notched specimen, the fatigue limit was determined by whether or not a crack propagated. The results can be interpreted as that hydrogen has no significant effect on crack initiation in the high-cycle fatigue regime and affected the threshold of the crack propagation.

    DOI: 10.1016/j.prostr.2019.12.056

  • A comparison of inhibitory effect of carbon monoxide and oxygen on hydrogen-accelerated fatigue crack growth Reviewed International journal

    Ryosuke Komoda, Kazuki Yamada, Masanobu Kubota

    Proceedings of the Twenty-ninth (2019) International Ocean and Polar Engineering Conference   4169 - 4174   2019.06

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    This study investigated effects of addition of O2 and CO to H2 gas environments on a hydrogen-accelerated fatigue crack growth in a pipe steel. Both O2 and CO inhibited the hydrogen-accelerated fatigue crack growth. The inhibitory effect of O2 was well-interpreted by the mechanism proposed by Somerday et al. (2013). On the other hand, different mechanisms, which are the reaction rate of CO with the iron surface and time for hydrogen diffusion in the material, dominated the inhibitory effect of CO.

  • Inhibition of hydrogen environment assisted cracking by small amount of oxygen contained in hydrogen gas Reviewed International journal

    Ryosuke Komoda, Masanobu Kubota, Aleksandar Staykov, Patrick Ginet, Francoise Barbier, Jader Furtado

    Proceedings of The 6th International Conference on Crack Paths (CP 2018)   377 - 382   2018.09

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    Fracture toughness tests of a pipe steel were conducted in hydrogen environments. The crosshead speed was 2.0 × 10-5 mm/s. The gas pressure was 0.6 MPa. The temperature was 293 K. Two gas systems were used to investigate the effect of a small amount of oxygen on hydrogen environment-assisted cracking (HEAC). One was a closed gas system, where a hydrogen gas is stored in the gas chamber. In this system, oxygen content in the gas chamber gradually increased with time and reached 1 vppm during the test. Another was an open gas system, where a high-purity hydrogen gas is continuously supplied into the gas chamber. In this system, the oxygen content in the gas chamber can be kept at 0.1 vppm. The fracture toughness in the hydrogen with 0.1 vppm oxygen was significantly lower than that in air. The fracture toughness in the hydrogen with the maximum oxygen content of 1 vppm was higher than that in the hydrogen with 0.1 vppm oxygen. 1 vppm oxygen partially inhibited the HEAC. Owing to a detailed analysis of the test results, the critical oxygen content to appear the inhibitory effect of oxygen under the test conditions could be estimated as 0.3 vppm.

  • Inhibition of hydrogen embrittlement of Cr-Mo steel by the addition of impurities to hydrogen environment and the effect of material strength Reviewed International journal

    Ryosuke Komoda, Masanobu Kubota, Shuichi Yoshida, Aleksandar Staykov, Patrick Ginet, Francoise Barbier, Jader Furtado

    The Proceedings of the 28th (2018) International Ocean and Polar Engineering Conference   236 - 242   2018.06

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    The effect of impurities, added to hydrogen environment, on hydrogen embrittlement (HE) was investigated in association with the effect of material strength. Addition of CO and O2 deactivated the HE. O2 prevented the HE with lower concentration than CO. Material with higher strength required larger amount of impurities to prevent the HE. Reduction of hydrogen uptake was the primary result of the addition of the impurities, but a certain amount of hydrogen uptake occurred when the HE was completely inhibited. Discussion regarding essential HE mechanisms for the fracture morphologies was required to interpret the effect of material strength.

  • The effects of oxygen impurities on fretting fatigue of austenitic stainless steel in hydrogen gas Invited Reviewed International journal

    Masanobu Kubota, Ryosuke Komoda, Jader Furtado

    Proceedings of 2016 International Hydrogen Conference   62 - 70   2017.08

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    To clarify the effect of O2 addition as an impurity in a H2 environment on the fretting fatigue strength of JIS SUS304 austenitic stainless steel, a control method to add ppm-level O2 to a H2 environment was established. The experiments were then carried out in H2 environments with O2 concentrations of 0.088, 5, 35 and 100 vppm. The fretting fatigue strength in the H2 was significantly reduced by the addition of a small amount of O2. The reduction was caused by the change in the stress conditions at the contact part due to the addition of O2 that changed the oxidation and fretting wear behavior on the fretted surface.

  • Development of new measurement method applying MEMS technology for relative slip measurement during fretting fatigue test in hydrogen Reviewed International journal

    Ryosuke Komoda, Nobutomo Morita, Fumiya Nakashima, Masanobu Kubota, Renshi Sawada

    Proceedings of 2016 International Hydrogen Conference   454 - 461   2017.08

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    An optical MEMS sensor device was developed to measure the relative slip range during fretting fatigue in hydrogen. The relative slip range is an important parameter to understand the mechanism of fretting fatigue failure, but there are measurement difficulties in a hydrogen environment. The MEMS sensor we developed showed a good reproducibility, accuracy and stability in hydrogen. For further improvement of the measurement, a calibration of the elastic deformation was done by both experiments and calculations. By applying this MEMS sensor, it was found that the relative slip range in hydrogen was significantly lower than that in air. This result was consistent with the experimental fact that adhesion between contacting surfaces occurred during fretting fatigue in hydrogen.

  • 水素雰囲気中フレッチング試験装置 Invited

    久保田祐信,薦田亮介

    トライボロジスト   61 ( 3 )   187 - 190   2016.03

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    Authorship:Last author   Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)

  • Fretting Fatigue in Hydrogen Environment Invited Reviewed

    Masanobu Kubota and Ryosuke Komoda

    Journal of Japanese Society of Tribologists   60 ( 10 )   651 - 657   2015.10

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    DOI: 10.18914/tribologist.60.10_651

  • Fretting fatigue properties under the effect of hydrogen and the mechanisms that cause the reduction in fretting fatigue strength International journal

    Jader Furtado, Ryosuke Komoda, Masanobu Kubota

    13th Proceedings of Internal Conference on Fracture   2013.06

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    Fretting fatigue, which is a composite phenomenon of metal fatigue and friction, is one of the major factors in the design of mechanical components as it significantly reduces fatigue strength. Since hydrogen can influence both fatigue and friction, fretting fatigue is one of the important concerns in designing hydrogen equipment. The authors carried out the fretting fatigue tests on austenitic stainless steels in order to characterize the effect of hydrogen and to explain the mechanism responsible for hydrogen embrittlement. In this study, the significant reduction in fretting fatigue strength due to hydrogen is shown including other factors influencing the fretting fatigue strength such as surface roughness, hydrogen content and the addition of oxygen. The cause of the reduction in the fretting fatigue strength in hydrogen is local adhesion between the contacting surfaces and subsequent formation of many small cracks. Furthermore, hydrogen enhances crack initiation under fretting fatigue conditions. Transformation of the microstructure from austenite to martensite is another possible reason. A hydrogen charge also reduces the fretting fatigue strength. The cause is the reduction in the crack growth threshold, ΔKth, due to hydrogen.

  • Considering the mechanisms causing reduction of fretting fatigue strength by hydrogen Reviewed International journal

    Masanobu Kubota, Yuki Shiraishi, Ryosuke Komoda, Yoshiyuki Kondo, Jader Furtado

    Proceedings of 19th European Conference on Fracture (ECF19)   2012.09

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  • Effect of hydrogen and addition of oxygen on fretting fatigue properties Reviewed International journal

    Masanobu Kubota, Yutaro Adachi, Yuki Shiraishi, Ryosuke Komoda, Jader Furtado, Yoshiyuki Kondo

    Proceedings of 2012 International Hydrogen Conference   391 - 399   2012.09

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Conference Prsentations (Oral, Poster)

  • Hydrogen-enhanced creep deformation of SUY-1 pure iron

    Kentarou Wada, Ryosuke Komoda, Toshihiro Tsuchiyama, Masanobu Kubota

    International Hydrogen Conference  2023.09  Engineering Conference International

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    Event date: 2023.09.17 - 2023.09.21   Language:English   Country:United States  

  • Mitigation of hydrogen embrittlement by carbon monoxide impurity in gaseous H2

    Ryosuke Komoda, Masanobu Kubota, Aleksandar Staykov, Patrick Ginet, Francoise Barbier, Jader Furtado, Laurent Prost, Akihide Nagao

    International Hydrogen Conference  2023.09  Engineering Conference International

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    Event date: 2023.09.17 - 2023.09.21   Language:English   Country:United States  

  • Mitigation of hydrogen embrittlment by addition of inhibitors to hydrogen gas Invited

    Ryosuke Komoda

    The Institute of Industrial Applications Engineers (IIAE) Annual Conference 2023  2023.09  The Institute of Industrial Applications Engineers

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    Event date: 2023.09.07   Language:Japanese   Country:Japan  

  • Study on the effect of impurities contained in hydrogen gas on hydrogen embrittlement Invited

    Ryosuke Komoda

    8th JSMS Kyushu brunch meeting  2021.11 

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    Event date: 2021.11.27   Language:Japanese   Country:Japan  

  • Inhibition of hydrogen embrittlement by small amount of oxygen contained in hydrogen gas Invited

    Ryosuke Komoda, Masanobu Kubota, Aleksandar Staykov, Patrick Ginet, Francoise Barbier, Jader Furtado

    HYDROGENIUS, I2CNER and HYDROMATE Joint Research Symposium  2019.01 

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    Event date: 2019.01.30   Language:English   Country:Japan  

  • Effect of material strength on inhibitory effect of carbon monoxide on hydrogen-assisted fracture

    Shuichi Yoshida, Ryosuke Komoda, Masanobu Kubota, Patrick Ginet

    2017.11 

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    Event date: 2017.11.25   Language:Japanese   Country:Japan  

  • Effect of addition of impurity to hydrogen-accelerated fatigue crack growth

    Kazuki Yamada, Ryosuke Komoda, Masanobu Kubota

    2017.11 

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    Event date: 2017.11.25   Language:Japanese   Country:Japan  

  • Effect of hydrogen on cyclic deformation behavior in low-cycle fatigue

    Koji Dohi, Masanobu Kubota, Ryosuke Komoda

    2017.11 

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    Event date: 2017.11.25   Language:Japanese   Country:Japan  

  • Development of New Measurement Method for Relative Slip Range in Fretting Fatigue Test in Hydrogen Environment Applying MEMS Micro-Encoder

    Ryosuke Komoda, Nobutomo Morita, Fumiya Nakashima, Masanobu Kubota, Renshi Sawada

    2017.10 

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    Event date: 2017.10.09   Language:Japanese   Country:Japan  

  • Fretting Fatigue in Hydrogen Containing ppm-levels of oxygen

    Ryosuke Komoda, Jader Furtado, Masanobu Kubota

    I2CNER Annual Symposium 2017,  2017.02 

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    Event date: 2017.02.01   Language:English   Country:Japan  

  • Fatigue Limit of SCM435 and XM-19 in High Pressure Hydrogen

    Mio Fukuda, Ryosuke Komoda, Masanobu Kubota, Takashi Soejima, Saburo Matsuoka

    2016.12 

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    Event date: 2016.12.10   Language:Japanese   Country:Japan  

  • Fretting fatigue in hydrogen Invited

    Masanobu Kubota, Ryosuke Komoda, Jader Furtado

    KRISS workshop  2016.11 

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    Event date: 2016.11.17   Language:English   Country:Korea, Republic of  

  • Effect of contact pressure on fretting fatigue failure of oil-well pipe material

    Daisuke Takazaki, Masanobu Kubota, Ryosuke Komoda, Yosuke Oku, Taizo Makino, Masaaki Sugino

    Asian Conference on Experimental Mechanics 2016 (ACEM 2016)  2016.11 

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    Event date: 2016.11.15   Language:English   Country:Korea, Republic of  

  • Fretting fatigue in hydrogen and the effect of oxygen impurity Invited

    Masanobu Kubota, Ryosuke Komoda, Jader Furtado

    Asian Conference on Experimental Mechanics 2016 (ACEM 2016)  2016.11 

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    Event date: 2016.11.15   Language:English   Country:Korea, Republic of  

  • Mechanism of Reduction in Fretting Fatigue Strength in Hydrogen by Addition of ppm-Levels of Oxygen

    Daisuke Takazaki, Ryosuke Komoda, Masanobu Kubota, Jader Furtado

    2016.09 

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    Event date: 2016.09.14   Language:Japanese   Country:Japan  

  • Development of new measurement method applying MEMS technology for relative slip measurement during fretting fatigue test in hydrogen

    Ryosuke Komoda, Nobutomo Morita, Fumiya Nakashima, Masanobu Kubota, Renshi Sawada

    2016 International Hydrogen Conference  2016.09 

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    Event date: 2016.09.14   Language:English   Country:United States  

  • Mechanism of Fretting Fatigue Failure at the Middle of Contact Surface for Oil-Well Pipe Material

    Daisuke Takazaki, Masanobu Kubota, Ryosuke Komoda, Yosuke Oku, Taizo Makino, Masaaki Sugino

    2016.09 

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    Event date: 2016.09.12   Language:Japanese   Country:Japan  

  • The effects of oxygen impurities on fretting fatigue of austenitic stainless steel in hydrogen gas

    Masanobu Kubota, Ryosuke Komoda, Jader Furtado

    2016 International Hydrogen Conference  2016.09 

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    Event date: 2016.09.12   Language:English   Country:United States  

  • Evaluation of local relative slip in a narrow space in hydrogen gas using MEMS optical encoder

    Nobutomo Morita, Ryosuke Komoda, Fumiya Nakashima, Masanobu Kubota, Eiji Higurashi, Renshi Sawada

    2016 International Conference on Optical MEMS and Nanophotonics (IEEE OMN 2016)  2016.08 

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    Event date: 2016.08.02   Language:English   Country:Singapore  

  • Fretting fatigue on thread root of premium threaded connections

    Yosuke Oku, Masaaki Sugino, Yoshinori Ando, Taizo Makino, Ryosuke Komoda, Masanobu Kubota

    8th International Symposium on Fretting Fatigue  2016.04 

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    Event date: 2016.04.19   Language:English   Country:Brazil  

  • Characterization of the effect of hydrogen on the microstructure change at the adhered spot during fretting fatigue

    Ryosuke Komoda, Masanobu Kubota

    8th International Symposium on Fretting Fatigue  2016.04 

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    Event date: 2016.04.19   Language:English   Country:Brazil  

  • Fatigue Limit of SCM435 Low-Alloy Steel in 115 MPa Hydrogen Gas

    Masanobu Kubota, Ryosuke Komoda, Saburo Matsuoka

    2016.03 

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    Event date: 2016.03.24   Language:Japanese   Country:Japan  

  • Fretting Fatigue in Hydrogen Gas and Effect of Impurities

    Ryosuke Komoda, Jader Furtado and Masanobu Kubota

    INTERNATIONAL HYDROGEN ENERGY DEVELOPMENT FORUM 2016  2016.02 

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    Event date: 2016.02.04   Language:English   Country:Japan  

  • Fretting Fatigue in Hydrogen Gas and Effect of Impurities

    Ryosuke Komoda, Jader Furtado and Masanobu Kubota

    I2CNER Annual Symposium 2016  2016.02 

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    Event date: 2016.02.02   Language:English   Country:Japan  

  • Application of MEMS Technology to Measurement of Relative Slip during Fretting Fatigue Test in Hydrogen

    Ryosuke Komoda, Nobutomo Morita, Nakashima Fumiya, Masanobu Kubota, Renshi Sawada

    2015.12 

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    Event date: 2015.12.12   Language:Japanese   Country:Japan  

  • Effect of Contact Pressure on Fretting Fatigue Failure Modes of Oil-Well Pipe Materials

    Daisuke Takazaki, Ryosuke Komoda, Masanobu Kubota, Yosuke Oku, Taizo Makino, Masaaki Sugino, Ayumu Nakahata

    2015.12 

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    Event date: 2015.12.12   Language:Japanese   Country:Japan  

  • Fretting fatigue properties in hydrogen containing impurities

    Ryosuke Komoda, Masanobu Kubota, Jader Furtado

    EUROMAT2015  2015.09 

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    Event date: 2015.09.23   Language:English   Country:Poland  

  • Mechanisms of reduction of fretting fatigue strength in hydrogen

    R. Komoda, M. Kubota

    2015.08 

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    Event date: 2015.08.10   Language:English   Country:Japan  

  • Microstructure Change during Fretting Fatigue in Hydrogen

    Ryosuke Komoda, Masanobu Kubota

    2015.05 

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    Event date: 2015.05.23   Language:Japanese   Country:Japan  

  • Effect of Addition of Oxygen and Water Vapor on Fretting Fatigue Properties in Hydrogen

    Ryosuke Komoda, Masanobu Kubota and Jader Furtado

    INTERNATIONAL HYDROGEN ENERGY DEVELOPMENT FORUM 2015  2015.02 

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    Event date: 2015.02.03   Language:English   Country:Japan  

  • Consideration of effects of minute amount of oxygen and water vapor on oxide removal and production behavior at fretted surface of SUS304 in hydrogen and relation of fretting fatigue strength

    Ryosuke Komoda, Masanobu Kubota, Jader Furtado

    2014.12 

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    Event date: 2014.12.13   Language:Japanese   Country:Japan  

  • Effect of addition of oxygen and water vapor on fretting fatigue properties in hydrogen

    Ryosuke Komoda, Masanobu Kubota, Jader Furtado

    Hy-SEA 2014  2014.10 

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    Event date: 2014.10.26   Language:English   Country:Brazil  

  • Effect of internal hydrogen on fretting fatigue strength of austenitic stainless steels and consideration on interaction of internal and environmental hydrogen

    Ryosuke Komoda, Naoto Yoshigai, Masanobu Kubota, Jader Furtado

    The seventh Kyushu University-KAIST Joint Workshop on Frontiers in Mechanical Engineering  2014.09 

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    Event date: 2014.09.26   Language:English   Country:Japan  

  • Effect of internal and environmental hydrogen on fretting fatigue strength

    Ryosuke Komoda, Naoto Yoshigai, Masanobu Kubota, Jader Furtado

    2014.09 

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    Event date: 2014.09.10   Language:Japanese   Country:Japan  

  • Effect of hydrogen on fretting fatigue properties

    Masanobu Kubota, Ryosuke Komoda, Jader Furtado

    2014.09 

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    Event date: 2014.09.10   Language:Japanese   Country:Japan  

  • Fretting fatigue property in hydrogen including oxygen or water vapor

    Ryosuke Komoda, Naoto Yoshigai, Masanobu Kubota, Jader Furtado

    2014.05 

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    Event date: 2014.05.18   Language:Japanese   Country:Japan  

  • The effect of impurities contained in hydrogen gas on fretting fatigue properties

    Ryosuke Komoda, Masanobu Kubotam Naoto Yoshigai, Jader Furtado

    2014.03 

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    Event date: 2014.03.14   Language:Japanese   Country:Japan  

  • Discussion on contribution of adhesion to the reduction in fretting fatigue strength

    Naoto Yoshigai, Ryosuke Komoda, Masanobu KUbotam Jader Furtado

    2014.03 

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    Event date: 2014.03.14   Language:Japanese   Country:Japan  

  • Reduction in fretting fatigue strength of austenitic stainless steels due to internal hydrogen

    Ryosuke Komoda, Naoto Yoshigai, Masanobu Kubota, Jader Furtado

    11th International Fatigue Congress 2014  2014.03 

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    Event date: 2014.03.03   Language:English   Country:Australia  

  • Fretting fatigue properties under the effect of hydrogen

    Ryosuke Komoda, Masanobu Kubota, Jader Furtado

    2013.10 

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    Event date: 2013.10.14   Language:Japanese   Country:Japan  

  • Effect of internal hydrogen on fretting fatigue strength of austenitic stainless steels

    Ryosuke Komoda, Naoto Yoshigai, Jader Furtado, Masanobu Kubota

    2013.09 

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    Event date: 2013.09.28   Language:Japanese   Country:Japan  

  • Fretting fatigue properties under the effect of hydrogen and mechanisms that cause the reduction in fretting fatigue strength

    Jader Furtado, Ryosuke Komoda, Masanobu Kubota

    13th International Conference of Fracture  2013.06 

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    Event date: 2013.06.19   Language:English   Country:China  

  • Fundamental mechanism causing reduction in fretting fatigue strength of SUS304

    Ryosuke Komoda, Masanobu Kubota, Yoshiyuki Kondo, Jader Furtado

    2013.05 

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    Event date: 2013.05.19   Language:Japanese   Country:Japan  

  • The mechanism causing reduction in fretting fatigue strength due to hydrogen

    Ryosuke Komoda, Masanobu Kubota, Yoshiyuki Kondo, Jader Furtado

    7th International Symposium on Fretting Fatigue  2013.04 

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    Event date: 2013.04.10   Language:English   Country:United Kingdom  

  • Effect of hydrogen and impurities on fretting fatigue properties

    Masanobu Kubota, Ryosuke Komoda, Yutaro Adachi, Yoshiyuki Kondo, Jader Furtado

    7th International Symposium on Fretting Fatigue  2013.04 

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    Event date: 2013.04.10   Language:English   Country:United Kingdom  

  • The effect of small amount of oxygen on fretting fatigue strength of austenitic stainless steel in hydrogen gas

    Yutaro Adachi, Ryosuke Komoda, Jader Furtado, Yoshiyuki Kondo, Masanobu Kubota

    2012.09 

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    Event date: 2012.09.23   Language:Japanese   Country:Japan  

  • Consideration the mechanisms causing reduction of fretting fatigue strength by hydrogen

    Masanobu Kubota, Yuki Shiraishi, Ryosuke Komoda, Yoshiyuki Kondo, Jader Furtado

    2012 International Hydrogen Conference  2012.09 

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    Event date: 2012.09.10   Language:English   Country:United States  

  • Effect of Hydrogen on Fatigue Strength of Mechanical Joint

    Yutaro Adachi, Yuki Shiraishi, Ryosuke Komoda, Masanobu Kubota, Yoshiyuki Kondo, Jader Furtado

    The sixth Kyushu University-KAIST Joint Workshop on Frontiers in Mechanical Engineering  2012.08 

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    Event date: 2012.08.31   Language:English   Country:Korea, Republic of  

  • Consideration the mechanisms causing reduction of fretting fatigue strength by hydrogen

    Masanobu Kubota, Yuki Shiraishi, Ryosuke Komoda, Yoshiyuki Kondo, Jader Furtado

    19th European Conference on Fracture (ECF19)  2012.08 

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    Event date: 2012.08.26   Language:English   Country:Russian Federation  

  • Role of adhesion to cause reduction of fretting fatigue strength in hydrogen gas

    Yuki Shiraishi, Ryosuke Komoda, Jader Furtado, Yoshiyuki Kondo, Masanobu Kubota

    2012.03 

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    Event date: 2012.03.16   Language:Japanese   Country:Japan  

  • Study on the mechanism causing reduction of fretting fatigue strength due to hydrogen gas

    Ryosuke Komoda, Yoshiyuki Kondo, Jader Furtado, Masanobu Kubota

    2012.03 

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    Event date: 2012.03.16   Language:Japanese   Country:Japan  

  • The effect of impurities containing hydrogen gas on fretting fatigue strength of austenitic stainless steel

    Yutaro Adachi, Ryosuke Komoda, Jader Furtado, Yoshiyuki Kondo, Masanobu Kubota

    2012.03 

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    Event date: 2012.03.16   Language:Japanese   Country:Japan  

  • Effect of Hydrogen and Adittion of Oxygen on Fretting Fatigue Properties

    Ryosuke Komoda, Yoshiyuki Kondo, Masanobu Kubota

    INTERNATIONAL HYDROGEN ENERGY DEVELOPMENT FORUM 2012  2012.02 

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    Event date: 2012.02.02   Language:English   Country:Japan  

  • Effect of hydrogen on fretting fatigue in SUS316 austenitic stainless steel

    Yuki Shiraishi, Yutaro Adachi, Ryosuke Komoda, Masanobu Kubota, Yoshiyuki Kondo, Jader Furtado

    2011.09 

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    Event date: 2011.09.13   Language:Japanese   Country:Japan  

  • ,振動荷重を受ける接触面の摩耗損傷に関する基礎的研究,A study of mechanical damage and wear on contact surface subjected to vibration

    Ryosuke Komoda, Shinji Hashimura, Yoshihiko Mori

    2010.03 

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    Event date: 2010.03.09   Language:Japanese   Country:Japan  

  • Control of hydrogen embrittlement by electric field

    Ayu Haneda, Ryosuke Komoda

    2024.03 

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    Event date: 2024.03.07   Language:Japanese   Country:Japan  

  • Effects of temperature and loading frequency on the mitigation of hydrogen-accelerated fatigue crack growth by addition of oxygen to hydrogen gas

    Reina Matsuo, Ryosuke Komoda

    2024.03 

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    Event date: 2024.03.07   Language:Japanese   Country:Japan  

  • フレッティング新生面におけるCO分解触媒作用に及ぼす試験片化学組成の影響

    小出尚寛,久保田祐信,薦田亮介

    日本材料学会九州支部 第9回学術講演会  2022.12 

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    Event date: 2022.12.03   Language:Japanese   Country:Japan  

  • Experimental and theoretical study on hydrogen embrittlement indeuced by ammonia

    Nan Zhang, Ryosuke Komoda, Masanobu Kubota, Aleksandar Staykov

    日本材料学会九州支部 第9回学術講演会  2022.12 

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    Event date: 2022.12.03   Language:Japanese   Country:Japan  

  • Effect of hydrogen on creep properties of SUY-1 industrial pure iron

    Kentaro Wada, Toru Yamashita, Daisuke Takazaki, Ryosuke Komoda, Masanobu Kubota

    JSME International Conference on Matarials and Processing 2022  2022.11 

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    Event date: 2022.11.06   Language:English   Country:Japan  

  • Effect of hydrogen on fatigue crack growth behavior of low alloy steels in methane

    Shunsuke Umezaki, Masanobu Kubota, Ryosuke Komoda, Naho Inoue, Hiroshi Okano, Tomoharu Ishida, Shusaku Takagi

    JSME International Conference on Matarials and Processing 2022  2022.11 

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    Event date: 2022.11.06   Language:English   Country:Japan  

  • Mitigation of hydrogen environment embrittlement of carbon steels A106 and A333 by addition of CO to H2 gas and its gas pressure dependence

    (3) Ryosuke Komoda, Masanobu Kubota, Aleksandar Staykov, Patrick Ginet, Francoise Barbier, Jader Furtado, Laurent Prost, Akihide Nagao

    Fourth International Conference on Metals & Hydrogen  2022.10 

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    Event date: 2022.10.11   Language:English   Country:Belgium  

  • Activation of catalyst for CO decomposition by chemimechanical effect of fretting

    Masanobu Kubota, Ryosuke Komoda, Yuki Nakamura

    10th International Symposium on Fretting Fatigue  2022.09 

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    Event date: 2022.09.19   Language:English   Country:Belgium  

  • Fretting fatigue properties in hydrogen gas containing ppm-levels of oxygen

    Ryosuke Komoda, Masanobu KUbota, Jader Furtado, Laurent Prost, Akihide Nagao

    10th International Symposium on Fretting Fatigue  2022.09 

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    Event date: 2022.09.19   Language:English   Country:Belgium  

  • Loading dependence of mitigation effect of CO on hydrogen embrittlement of pure iron and low carbon steel

    Ryosuke Komoda, Masanobu Kubota, Aleksandar Staykov, Patrick Ginet, Jader Furtado, Laurent Prost, Akihide Nagao

    Thirty-second (2022) International Ocean and Polar Engineering Conference  2022.06 

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    Event date: 2022.06.05   Language:English   Country:China  

  • Hydrogen embrittlement properties of low alloy steel in H2 added CH4 gas

    Shunsuke Umezaki, Masanobu Kubota, Ryosuke Komoda, Naho Inoue, Hiroshi Okano, Tomoharu Ishida, Shusaku Takagi

    2022.03 

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    Event date: 2022.03.09   Language:Japanese  

  • Effect of hydrogen on creep properties

    Masanobu Kubota, Daisuke Takazaki, Ryosuke Komoda, Kentaro Wada, Toshihiro Tsuchiyama, Mohsen Dadfarnia, Brian Somerday, Petros Sofronis

    TMS2022 Annual Meeting & Exhibition  2022.02 

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    Event date: 2022.02.28   Language:English   Country:United States  

  • Characterization of hydrogen embrittlement properties of low alloy steels in CH4 and H2 mixed gas

    Shunsuke Umezaki, Masanobu Kubota, Ryosuke Komoda, Naho Inoue, Hiroshi Okano, Tomoharu Ishida, Shusaku Takagi

    6th Asian Symposium on Material and Processing 2022  2022.01 

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    Event date: 2022.01.26   Language:English  

  • Effect of chromium alloy element on CO mitigation effect on gaseous hydrogen environment embrittlement of ferritic steel

    Nan Zhang, Ryosuke Komoda, Masanobu Kubota, Aleksandar Staykov

    8th JSMS Kyushu brunch annual meeting  2021.11 

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    Event date: 2021.11.27   Language:English   Country:Japan  

  • Effect of hydrogen on creep properties of SUS304, SUS304L, SUS310S and SUY-1

    Kentaro Wada, Toru Yamashita, Masanobu Kubota, Toshihiro Tsuchiyama, Ryosuke Komoda, Petros Sofronis, Brian Somerday, Mohsen Dadfarnia

    2021.09 

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    Event date: 2021.09.15   Language:English   Country:Japan  

  • Torsional fatigue of SUS304N1 austenitic stainless steel with small scratches

    Kenta Kuwahara, Ryosuke Komoda, Masahiro Endo and Junji Shirai

    Eighth International Conference on Very High Cycle Fatigue (VHCF8)  2021.07 

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    Event date: 2021.07.09   Language:English  

  • Development of an evaluation method for the effects of small amount of gas impurities contained in hydrogen gas on hydrogen permeation behavior into steel

    Ryosuke Komoda

    2021.03 

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    Event date: 2021.03.10   Language:Japanese  

  • SUS304N1のねじり疲労強度に及ぼす線傷の影響

    桑原 健太、薦田 亮介、遠藤 正浩、林 友、白井 純二

    日本機械学会九州支部第74期総会・講演会  2021.03 

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    Event date: 2021.03.10   Language:Japanese   Country:Japan  

  • Effect of hydrogen on fretting fatigue strength

    Masanobu Kubota, Ryosuke Komoda

    2nd Korea-Tribology International Symposium  2020.11 

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    Event date: 2020.11.29   Language:English  

  • Effect of ammonia impurity on gaseous hydrogen environment embrittlement of SCM440 low-alloy steel

    Nan Zhang, Ryosuke Komoda, Masanobu Kubota, Aleksandar Staykov

    日本材料学会九州支部第7回学術講演会  2020.11 

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    Event date: 2020.11.28   Language:English   Country:Japan  

  • Torsional Fatigue Strength of SUS304N1 with Small Scratches

    Kenta Kuwahara, Ryosuke Komoda, Masahiro Endo, Yu Hayashid, Junji Shiraid

    Asia-Pacific Conference on Fracture and Strength 2020 (APCFS2020)  2020.11 

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    Event date: 2020.11.05   Language:English   Country:Korea, Republic of  

  • Effect of ammonia impurity on hydrogen embrittlement of SCM440 low-alloy steel in hydrogen gas

    Zhang Nan, Ryosuke Komoda, Kazuki Yamada, Cynthia A Volkert, Lin Tian, Reiner Kirchheim, Petros Sofronis, Hosseinisarani Zahra, Mohsen Dadfarnia, Masanobu Kubota, Aleksandar Staykov

    The Thirtieth (2020) International Ocean and Polar Engineering Conference  2020.10 

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    Event date: 2020.10.13   Language:English  

  • Establishment of the quantitative evaluation method for the inhibitory effect of impurities contained in hydrogen gas on hydrogen permeation into steel

    Ryosuke Komoda

    2020.03 

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    Event date: 2020.03.18   Language:Japanese   Country:Japan  

  • Difference of controlling mechanisms of CO and O2 inhibitory effect s to hydrogen-assisted fatigue crack growth

    Kazuki Yamada, Ryosuke Komoda, Masanobu Kubota

    6th JSMS Kyushu brunch annual meeting  2019.12 

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    Event date: 2019.12.01   Language:Japanese   Country:Japan  

  • Effect of manganese phosphate coating on fretting fatigue strength of oil-well pipe material under grease lubrication

    Suzuko Hosoi, Daisuke Takazaki, Masanobu Kubota, Ryosuke Komoda, Yosuke Oku, Taizo Makino, Masaaki Sugino

    6th JSMS Kyushu brunch annual meeting  2019.12 

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    Event date: 2019.12.01   Language:Japanese   Country:Japan  

  • Effect of sort of steel on impurity gas inhibition to hydrogen-assisted crack growth

    Sawaki Sera, Ryosuke Komoda, Kazuki Yamada, Masanobu Kubota

    6th JSMS Kyushu brunch annual meeting  2019.12 

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    Event date: 2019.12.01   Language:Japanese   Country:Japan  

  • Elucidation of the effect of ppm-levels of oxygen addition to the environment on fretting fatigue properties in hydrogen gas and its mechanism

    Ryosuke Komoda, Masanobu Kubota, Jader Furtado

    The 27th Material Processing Technical Conference (M&P2019)  2019.11 

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    Event date: 2019.11.22   Language:Japanese   Country:Japan  

  • Effect of hydrogen in fatigue limit of SCM435 low-alloy steel

    Masanobu Kubota, Mio Fukuda, Ryosuke Komoda

    Fatigue Design 2019  2019.11 

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    Event date: 2019.11.21   Language:English   Country:France  

  • Effects of coating and lubrication on fretting fatigue properties of oil-well pipe material

    Suzuko Hosoi, Daisuke Takazaki, Masanobu Kubota, Ryosuke Komoda, Yosuke Oku, Taizo Makino, Masaaki Sugino

    International Conference on Advances Technology in Experimental Mechanics 2019 (ATEM'19)  2019.10 

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    Event date: 2019.10.10   Language:English   Country:Japan  

  • A comparison of inhibitory effects of carbon monoxide and oxygen on hydrogen-accelerated fatigue crack growth

    Ryosuke Komoda, Kazuki Yamada, Masanobu Kubota

    The Twenty-ninth International Ocean and Polar Engineering Conference  2019.06 

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    Event date: 2019.06.19   Language:English   Country:United States  

  • Consideration on the effect of hydrogen on fatigue limit

    Masanobu Kubota, Mio Fukuda, Ryosuke Komoda

    World Hydrogen Technologies Convention 2019  2019.06 

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    Event date: 2019.06.03   Language:English   Country:Japan  

  • The effect of addition of oxygen and carbon monoxide on hydrogen-assisted fatigue crack growth in conjunction with loading frequency

    Kazuki Yamada, Ryosuke Komoda, Masanobu Kubota

    68th JSMS annual meeting  2019.05 

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    Event date: 2019.05.25   Language:Japanese   Country:Japan  

  • Effect of hydrogen on low-cycle fatigue properties of SUS304

    Masanobu Kubota, Shuichi Yoshida, Koji Dohi, Ryosuke Komoda

    68th JSMS annual meeting  2019.05 

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    Event date: 2019.05.25   Language:Japanese   Country:Japan  

  • The Effectiveness of CO Chemical Coating in Conjunction with the Effect of Loading Frequency on the Hydrogen -Assisted Fatigue Crack Growth

    Kazuki Yamada, Ryosuke Komoda, Masanobu KUbota

    5th JSMS Kyushu brunch annual meeting  2018.12 

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    Event date: 2018.12.16   Language:Japanese   Country:Japan  

  • Effects of coating and lubrication on fretting fatigue properties of oil-well pipe material

    Suzuko HOSOI, Daisuke TAKAZAKI, Masanobu KUBOTA, Ryosuke KOMODA, Yosuke OKU, Taizo MAKINO and Masaaki SUGINO

    5th JSMS Kyushu brunch annual meeting  2018.12 

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    Event date: 2018.12.16   Language:Japanese   Country:Japan  

  • Effect of hydrogen on low-cycle fatigue behavior of SUS304 austenitic stainless steel

    Masanobu Kubota, Shuichi Yoshida, Koji Dohi, Ryosuke Komoda

    The 5th Asian Symposium on Materials and Processing (ASMP2018)  2018.12 

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    Event date: 2018.12.08   Language:English   Country:Thailand  

  • Effect of hydrogen on fatigue limit of SCM435 Cr-Mo steel

    Mio Fukuda, Masanobu Kubota, Ryosuke Komoda

    The 5th Asian Symposium on Materials and Processing (ASMP2018)  2018.12 

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    Event date: 2018.12.08   Language:English   Country:Thailand  

  • Effect of flatness of contact surface on fretting fatigue strength

    Daisuke Takazaki, Masanobu Kubota, Ryosuke Komoda, Suzuko Hosoi, Yosuke Oku, Taizo Makino, Masaaki Sugino

    The 5th Asian Symposium on Materials and Processing (ASMP2018)  2018.12 

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    Event date: 2018.12.08   Language:English   Country:Thailand  

  • The effect of carbon monoxide inhibitor against the accelerated fatigue crack growth in gaseous hydrogen and its loading frequency dependency

    Kazuki Yamada, Ryosuke Komoda, Masanobu Kubota

    2018.10 

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    Event date: 2018.10.16   Language:Japanese   Country:Japan  

  • Inhibition of hydrogen environment assisted cracking by small amount of oxygen contained in hydrogen gas

    Ryosuke Komoda, Masanobu Kubota, Aleksandar Staykov, Patrick Ginet, Francoise Barbier, Jader Furtado

    The 6th International Conference on Crack Oaths (CP 2018)  2018.09 

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    Event date: 2018.09.21   Language:English   Country:Italy  

  • Effects of Hydrogen and Weld Defect on Tensile Properties of SUH660 and SUS316L Welded Joints

    Masanobu Kubota, Xuesong Cui, Ryosuke Komoda, Hiroshi Wakabayashi, Yasuhisa Tanaka

    2018 3rd International Conference on Design, Materials and Manufacturing (ICDMM 2018)  2018.08 

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    Event date: 2018.08.12   Language:English   Country:Japan  

  • Inhibition of hydrogen embrittlement of Cr-Mo steel by the addition of impurities to hydrogen environment and the effect of material strength

    Ryosuke Komoda, Masanobu Kubota, Shuichi Yoshida, Aleksandar Staykov, Patrick Ginet, Francoise Barbier, Jader Furtado

    The Twenty-eighth (2018) International Ocean and Polar Engineering Conference  2018.06 

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    Event date: 2018.06.13   Language:English   Country:Japan  

  • Effect of material strength on inhibition of carbon monoxide by the addition of hydrogen-assisted fracture

    Shuichi Yoshida, Ryosuke Komoda, Masanobu Kubota, Aleksandar Staykov, Patrick Ginet, Francoise Barbier, Jader Furtado

    2018.05 

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    Event date: 2018.05.27   Language:Japanese   Country:Japan  

  • Effect of Hydrogen on Fatigue Limit and Slip Bands of High-strength Steel

    Mio Fukuda, Masanobu Kubota, Ryosuke Komoda

    2018.03 

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    Event date: 2018.03.16   Language:Japanese   Country:Japan  

  • Effect of material strength and species of gas impurity on inhibition of hydrogen-induced fracture by gas impurities

    Ryosuke Komoda, Shuichi Yoshida, Masanobu Kubota, Patrick Ginet

    2018.03 

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    Event date: 2018.03.16   Language:Japanese   Country:Japan  

  • Inhibition of hydrogen embrittlement of Cr-Mo steel by the addition of impurities to hydrogen environment and the effect of material strength

    Shuichi Yoshida, Ryosuke Komoda, Masanobu Kubota, Aleksandar Staykov, Patrick Ginet, Francoise Barbier and Jader Furtado

    HYDROGENIUS, I2CNER and HYDROMATE Joint Research Symposium  2018.02 

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    Event date: 2018.02.02   Language:English   Country:Japan  

  • Inhibitory effect of oxygen on hydrogen-induced fracture of A333 pipe steel

    Ryosuke Komoda, Masanobu Kubota, Aleksandar Staykov, Patrick Ginet, Francoise Barbier, Jader Furtado

    HYDROGENIUS, I2CNER and HYDROMATE Joint Research Symposium  2018.02 

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    Event date: 2018.02.02   Language:English   Country:Japan  

  • Effect of CO addition to hydrogen environment on fatigue crack growth propagation behavior

    Kazuki Yamada, Ryosuke Komoda, Masanobu Kubota

    HYDROGENIUS, I2CNER and HYDROMATE Joint Research Symposium  2018.02 

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    Event date: 2018.02.02   Language:English   Country:Japan  

  • Inhibition of hydrogen embrittlement by gas impurities

    Ryosuke Komoda, Masanobu Kubota, Shuichi Yoshida, Kazuki Yamada, Aleksandar Staykov, Patrick Ginet, Francoise Barbier, Jader Furtado

    I2CNER Annual Symposium 2018  2018.01 

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    Event date: 2018.01.31   Language:English   Country:Japan  

  • 異種材溶接継手の引張強度特性に及ぼす水素の影響

    崔雪松,薦田亮介,久保田正信

    Q-PIT アニュアルシンポジウムポスター発表会  2018.01 

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    Event date: 2018.01.30   Language:Japanese   Country:Japan  

  • 高強度材料における疲労限度とそのすべり帯に及ぼす水素の影響

    福田未央,久保田正信,薦田亮介

    Q-PIT アニュアルシンポジウムポスター発表会  2018.01 

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    Event date: 2018.01.30   Language:Japanese   Country:Japan  

  • 水素ぜい化防止に関する研究

    吉田修一,山田和輝,薦田亮介,久保田正信

    Q-PIT アニュアルシンポジウムポスター発表会  2018.01 

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    Event date: 2018.01.30   Language:Japanese   Country:Japan  

  • Fatigue limit of high-strength material in hydrogen

    Mio Fukuda, Masanobu Kubota, Ryosuke Komoda

    2017.11 

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    Event date: 2017.11.25   Language:Japanese   Country:Japan  

  • Effect of Hydrogen on Tensile Strength Properties of Different Material Welding Joint

    Xuesong Cui, Masnaobu Kubota, Ryosuke Komoda, Hiroshi Wakabayashi, Yasuhisa, Tanaka

    2017.11 

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    Event date: 2017.11.25   Language:Japanese   Country:Japan  

  • Effect of contact pressure on fretting fatigue properties of oil-well pipe material

    Daisuke Takazaki, Masanobu Kubota, Ryosuke Komoda, Yosuke Oku, Taizo Makino, Masaaki Sugino

    2017.11 

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    Event date: 2017.11.25   Language:Japanese   Country:Japan  

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Lectures

  • Hydrogen embrittlement

    2023.09 

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    Event date: 2023.09.09   Language:Japanese   Presentation type:Invited lecture   Venue:Kitakyushu, Fukuoka   Country:Japan  

Honors and Awards

  • Professor Award 2021

    The Society of Materials Science, Japan, Kyushu Branch   2021.11.27

    Ryosuke Komoda

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    Country:Japan

  • Division Award

    Materials and Processing Division The Japan Society of Mechanical Engineering   2020.09.14

    Ryosuke Komoda

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    Country:Japan

  • Kyushu University Student Award

    Kyushu University   2017.03.24

    Ryosuke Komoda

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    Country:Japan

  • Young Researcher Award

    The Society of Materials Science, Japan, Kyushu Branch   2015.12.12

    Ryosuke Komoda

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    Country:Japan

  • Best presentation at 63th JSMS annual meeting

    The Society of Materials Science, Japan   2015.03.26

    Ryosuke Komoda

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    Country:Japan

  • Young Presentation Fellow Award

    The Japan Society of Mechanical Engineers   2014.03.14

    Ryosuke Komoda

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    Country:Japan

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Grants-in-Aid for Scientific Research

  • Mitigation and promotion of hydrogen gas environment embrittlement by controlling electron density of material surface

    Grant number:22K18763  2022.04 - 2025.03   Grant-in-Aid for Challenging Research (Pioneering)

  • Quantitative evaluation of mitigation effect of gas impurities contained in hydrogen gas on hydrogen permeation

    Grant number:20K14616  2020.04 - 2022.03   Grant-in-Aid for Early-Career Scientists

  • Elucidation of Inhibitory Effect of Gas Impurities on Hydrogen-Induced Fracture and Effect of various factors

    Grant number:17H06930  2017.08 - 2019.03   Grant-in-Aid for Research Activity start-up

  • Elucidation of Mechanisms and establishment of quantitative evaluation method for effect of hydrogen on fretting fatigue

    Grant number:15J03650  2015.04 - 2017.03   Grant-in-Aid for JSPS Fellows

  • Establishment of material science for high-temperature hydrogen creep fracture

    Grant number:20H00218  2020.04 - 2023.03   Grant-in-Aid for Scientific Research(A)

Contracts

  • Evaluation of strength properties of roll materials

    2020.04 - 2022.12

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    Grant type:Joint research

  • Study on torsional fatigue strength of spring steels having small defects

    2020.04 - 2022.03

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    Grant type:Joint research

Other External Funds

  • Study on a Technology to Inhibit Hydrogen Embrittlement using Active Barrier Coating by Gas Impurities

    2018.04 - 2020.03

    ISIJ Research Promotion Grant  

Charge of off-campus class subject

  • Engieering Mechanics I

    2018.10 - 2022.12   Institution:Fukuoka University

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    Level:undergraduate_special_subjects  Country:Japan

  • Exercises of Mechanical Engineering Design A

    2018.10 - 2022.12   Institution:Fukuoka University

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    Level:undergraduate_special_subjects  Country:Japan

Activities of Academic societies and Committees

  • The Society of Materials Science, Japan   JSMS Committee on Fatigue of Materials  

    2017.05