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DOI： 10.2355/isijinternational.ISIJINT-2023-326

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.2355/tetsutohagane.TETSU-2023-049

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DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2023-070

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DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2023-100

Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2023-053

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2023-057

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2023-095

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2023-069

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2023-072

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2023-107

Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Iron and Steel Institute of Japan  

<p>The effects of retained austenite upon softening during low-temperature tempering at 373 K were investigated using martensitic carbon steels with and without retained austenite. To increase the amount of retained austenite, 10 mass% Ni was added to the base carbon steel (Fe-0.3C alloy). During tempering, the hardness decreased more rapidly in the Ni-added steel containing 6 vol.% retained austenite than in the base steel without retained austenite. Analyses of the microstructure and the carbon content in the solid solution (<i>i.e.</i>, the solute carbon concentration) revealed that the retained austenite tended to suppress carbide precipitation and significantly reduced the solute carbon concentration in the martensitic matrix. We demonstrated that retained austenite acts as an effective absorption site for solute carbon in the martensitic matrix; however, the partitioned carbon is unevenly localized near the martensite/austenite interface, owing to the poor diffusivity at 373 K.</p>

DOI： 10.2355/isijinternational.isijint-2023-100

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Language：Japanese   Publisher：The Iron and Steel Institute of Japan  

<p>The strengthening mechanism of ausforming in martensitic steels is believed to be due to the inheritance of dislocations in austenite by the subsequently transformed martensite. However, no studies to date have quantified the dislocation density before and after ausforming. In this study, the dislocation densities of Fe-5%Mn-C alloys were analyzed, and the relationship between hardening by ausforming and dislocation accumulation, as well as the effect of carbon on this relationship, were investigated. The hardness of ausformed martensite increased with the ausforming reduction in austenite, and the strengthening effect of ausforming increased with the addition of carbon. Similarly, the dislocation density of ausformed martensite increased with the ausforming reduction in austenite, and the dislocation accumulation by ausforming increased with the addition of carbon. Because the hardness of the ausformed martensite follows the Bailey–Hirsch relationship, the strengthening mechanism owing to ausforming could be explained by dislocation strengthening. To understand the dislocation accumulation process during ausforming, the dislocation density of austenite immediately after ausforming was measured by in-situ heating neutron diffraction. Consequently, the dislocation density of the ausformed austenite was not dependent on the carbon content, indicating that dislocations are not inherited in carbon-free steels. By contrast, in steels with sufficient carbon content, not only are dislocations inherited but additional dislocations are introduced during martensitic transformation.</p>

DOI： 10.2355/tetsutohagane.tetsu-2024-092

CiNii Research

Language：English   Publisher：The Iron and Steel Institute of Japan  

<p>To control the strength-ductility balance of type 304 metastable austenitic stainless steel, it is effective to perform annealing after partially deformation-induced transformation to change the properties of deformation-induced martensite and retained austenite. However, the changes in each microstructure and partitioning of alloying elements after annealing are not necessarily clear. In this study, the dual-phase microstructures of deformation-induced martensite and retained austenite in partially transformed type 304 stainless steel were annealed under different conditions, and the mechanical properties of each phase were investigated. The partially transformed specimen, which was subjected to 30% cold rolling after solution treatment at 1373 K-1.8 ks, has a dual-phase microstructure with approximately 70% deformation-induced martensite and 30% retained austenite. When annealing at 673 and 773 K, the austenite fraction did not change significantly; however, when annealing at 873 K, a reverse transformation occurred, and the austenite fraction increased to approximately 80%. Tensile tests revealed that the cold-rolled specimen exhibited a high yield stress of 1200 MPa and excellent ductility, with a total elongation of 15% owing to the TRIP effect. The yield stress increased at 673 K annealing but decreased at higher annealing temperatures. However, as a result of the nanoindentation tests, the hardness of both martensite and austenite hardly increased, even in the 673 K-annealed specimen, although its yield strength was increased. Therefore, it is presumed that the strength of the interface increased, and the interface became a strong obstacle to dislocation motion.</p>

DOI： 10.2355/isijisss.2024.0_177

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Iron and Steel Institute of Japan  

<p>In ferritic steels, the grain boundary segregation of carbon at ferrite grain boundaries increases the Hall–Petch coefficient and enhances grain refinement strengthening. It is also possible to further enhance the grain refinement strengthening by promoting carbon segregation through low-temperature aging or other methods. On the other hand, carbon content has a significant effect on the contribution of grain refinement strengthening in martensitic steels. By considering martensitic steels in the same manner as ferritic steels, it was speculated that a "hard block boundary" could be designed if carbon could be used more effectively. In this report, we discuss the effect of carbon on grain refinement strengthening and its ability to control the mechanical properties of martensitic steels based on a review of previous studies and newly conducted experiments.</p>

DOI： 10.2355/isijisss.2024.0_135

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Language：English   Publisher：The Japan Society for Technology of Plasticity  

<p>This study investigates the work-hardening behavior of a 5 %-Mn high-strength steel sheet in a warm temperature range up to 200 °C. This study was motivated by the known strong temperature dependence of the transformation-induced plasticity (TRIP) effect in this temperature range and need for accurate work-hardening curves for finite element (FE) simulations in press-forming applications for automobiles. Conventional tensile tests with elongation measurements cannot accurately evaluate the work-hardening curves of this steel because of the nonuniform deformation caused by large Lüders elongation, which exhibits approximately 0.1 yield elongation. To overcome this challenge, we employed real-time diameter change measurements converted to true strain to assess local work-hardening at warm temperatures. Key findings include: (1) strong temperature dependence of work-hardening curves up to 100 °C due to TRIP effect suppression with optimal uniform elongation at 75 °C; (2) temperature-independent stress plateau corresponding to Lüders deformation up to 100 °C; and (3) constant fracture strain across temperatures despite significant improvements in uniform elongation. These results provide crucial insights for optimizing press-forming processes and enhancing FE simulations for medium-Mn high-strength steel sheets.</p>

DOI： 10.9773/sosei.240702

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Publishing type：Research paper (scientific journal)   Publisher：Steel Research International  

Hall–Petch relationships at room temperature and lower temperatures are investigated for 316L steel (low-N steel) and 0.43% nitrogen-added 316L steel (high-N steel) produced by solution nitriding. The yield stress is separated into thermal and athermal components, and the effects of nitrogen on the former are clarified. In the case of low-N steel, the yield stress increases as the temperature decreases, and the degree of the increase is greater for fine-grained steels. This is not only due to the increase in friction stress (including solid solution strengthening) but also results from the increase in grain refinement strengthening caused by the increase in the Hall–Petch coefficient at low temperatures. By contrast, in high-N steel, the temperature dependence of the yield stress is more remarkable than in low-N steel. However, the amount of increase in friction stress at low temperatures is not very different between the low-N and high-N steels. Instead, the increase in grain refinement strengthening caused by nitrogen is greatly enhanced at lower temperatures. This result suggests that the combination of nitrogen addition and grain refining is very effective at strengthening austenitic steels under low temperatures.

DOI： 10.1002/srin.202200428

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Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Iron and Steel Institute of Japan  

<p>The relationship between hardness and solute carbon concentration estimated via electrical resistivity measurement was investigated in as-quenched and tempered martensitic steels containing carbon of 0.3-0.6 mass%. As a result of corelating the amount of hardening due to carbon in solid solution with the solute carbon concentration, by the calculation to subtract precipitation strengthening, grain refinement strengthening, dislocation strengthening, and softening due to retained austenite from the total strengthening, we derived an equation of solid solution strengthening, where the hardening increases proportionally to the 1 / 2 or 2 / 3 power of the solute carbon concentration. It was confirmed that the effects of the factors other than solid solution strengthening due to carbon on hardness are relatively small in tempered specimens when the tempering temperature is less than 673 K; therefore, the change in hardness in tempered martensitic steels can be mostly explained by solute carbon concentration regardless of carbon content.</p>

DOI： 10.2355/tetsutohagane.tetsu-2023-002

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2023-002

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Iron and Steel Institute of Japan  

<p>The relationship between hardness and solute carbon concentration estimated via electrical resistivity measurement was investigated in as-quenched and tempered martensitic steels containing carbon of 0.3–0.6 mass%. As a result of corelating the amount of hardening due to carbon in solid solution with the solute carbon concentration, by the calculation to subtract precipitation strengthening, grain refinement strengthening, dislocation strengthening, and softening due to retained austenite from the total strengthening, we derived an equation of solid solution strengthening, where the hardening increases proportionally to the 1/2 or 2/3 power of the solute carbon concentration. It was confirmed that the effects of the factors other than solid solution strengthening due to carbon on hardness are relatively small in tempered specimens when the tempering temperature is less than 673 K; therefore, the change in hardness in tempered martensitic steels can be mostly explained by solute carbon concentration regardless of carbon content.</p>

DOI： 10.2355/isijinternational.isijint-2022-416

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2022-111

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2022-081

Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2022-416

Language：Japanese   Publisher：Steering Committee on Japan Conference on Structural Safety and Reliability  

<p>The objective of this study is to characterize the effect of hydrogen on the creep properties of pure iron. Elucidation of mechanism that hydrogen affects creep deformation is essentially important to ensure the safety of evolving high-temperature hydrogen technologies. The material was JIS SUY-1 industrial pure iron, because its simple chemical composition and pure single phase may facilitate the consideration of the mechanism. Creep testing was carried out in argon and hydrogen gases at 873 K. The absolute gas pressure at which the creep tests were carried out was 0.12 MPa. The estimated hydrogen concentration in the specimen at the relevant conditions was estimated to be 0.70 mass ppm. Hydrogen accelerated the creep strain rate resulting in a significant reduction in the creep life. The fracture profile shows double cup fracture and fracture surface was dimple in both argon and hydrogen environments. There were no significant differences in the shape and size of the dimples depending on the environment. This observation indicated that hydrogen accelerated the creep deformation without changing the creep deformation mechanism. This consideration is similar to the creep of SUS304 stainless steel in hydrogen, which we previously carried out. A similar mechanism that hydrogen may increase the vacancy density, leading to enhanced dislocation climb, may be adopted.</p>

DOI： 10.60316/jcossar.10.0_341

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Language：Japanese   Publisher：The Iron and Steel Institute of Japan  

<p>To clarify the effect of alloying elements (M) on the grain boundary segregation behavior of boron (B) and carbon (C) in α-iron, the grain boundary segregation of B, C and alloying elements was evaluated thermodynamically for the Fe–B–1.0 at.%M and the Fe–C–1.0 at.%M ternary systems (M: Al, Ti, V, Cr, Mn, Nb, Mo) using the parallel tangent law proposed by Hillert. In this calculation, the Gibbs energies of the liquid phase in the Fe–B–M and Fe–C–M ternary systems were applied to those of the grain boundaries. According to the calculated results, in the Fe–B–M ternary systems, co-segregation of Ti, V, Mn or Nb with B was predicted, while no co-segregation behavior was confirmed in the case of Al, Cr or Mo addition; in the Fe–C–M ternary systems, co-segregation of Ti, V, Nb or Mo with C was predicted, while no co-segregation behavior was confirmed in the case of Al, Cr or Mn addition. These co-segregation tendencies correspond well with the formation tendencies of metal borides or metal carbides. Although the present calculated results were based on the assumption that substitutional elements can diffuse sufficiently in addition to interstitial elements B and C, we proposed an equation for the parallel tangent law under paraequilibrium condition in which no partitioning of substitutional elements occurs.</p>

DOI： 10.2355/tetsutohagane.tetsu-2022-081

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Publisher：28th IFHTSE 2023 Congress  

The hardness of martensitic steels increases with increasing carbon content due to the solid solution strengthening by carbon. However, in steels with high Ms temperature (C<0.4%), the hardness decreases due to auto-tempering after the martensite transformation. The degree of tempering can be quantitatively evaluated from the integrated diffusion area S (=ΣDt) where D is the diffusion coefficient of carbon in bcc-Fe and t is the holding time. True hardness HV* without the effect of auto-tempering is expressed by the equation; HV* = 1.75 + 8.2 × (mass%C)1/2. When the hardness of as-quenched martensite is HV, the standardized hardness Hs is expressed by Hs =HV/HV*. It was confirmed that the equation: Hs=1.0-0.0052×{18+(logS)}2 is realized in the relation between S and Hs. In this study, cooling curves were obtained at many points in a Jominy end-quench test piece and the S-values were calculated from the cooling curves for the temperature range below the M50 temperature. The calculated S-values give the hardness at each point in a Jominy end-quench test piece and the calculated hardness was compared with experimental data. As a result, it was found that significant decrease in hardness occurs within 1 mm from the quenching edge but the calculated hardness agrees well with the experimental data in the points far from the quenching edge more than 1mm.

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Iron and Steel Institute of Japan  

<p>Fe-0.4C-1.2Si-0.8Mn (mass%) alloys austenitized at different temperatures, ranging from 1103 to 1473 K, were subjected to interrupted quenching (IQ) at 473 K and then maintained at that temperature to induce the partitioning of carbon from martensite to austenite (one-step quenching and partitioning (Q&P) process). The initial austenite grain size before the IQ was varied from 20 to 573 μm. As the initial austenite grain size becomes finer, the enrichment of carbon in the untransformed austenite during the partitioning treatment is enhanced, which leads to a greater increase in the volume fraction of retained austenite. The reasons for the increased carbon enrichment were explained by the effective carbon partitioning as well as the promoted bainitic transformation, which were both caused by the increase in the area of the martensite/austenite interface. Tensile tests of the specimens with different initial austenite grain sizes revealed that the mechanical properties of the one-step Q&P specimens improved in both strength and elongation by the refinement of the initial austenite grains.</p>

DOI： 10.2355/tetsutohagane.tetsu-2022-111

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Publisher：28th IFHTSE 2023 Congress  

Fe-5Mn-0.1C alloy was subjected to interrupted quenching to a temperature between Ms and Mf followed by intercritical annealing in the ferrite and austenite dual-phase region. As a result, a core-shell type second phase, which consisted of a fresh martensite core surrounded by a film-like retained austenite shell, was formed. Characteristics of the microstructure and mechanical properties of the medium Mn steel with core-shell type second phase will be introduced.

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Publisher：28th IFHTSE 2023 Congress  

The microstructure formation of Fe-5Mn-0.1C-1.2Si (mass%) steel during and after reversion from martensite to austenite were observed by SEM/EBSD method, and then, the grain refinement mechanism by annealing after cold rolling in medium Mn steel was discussed from the viewpoint of the crystallographic characteristics of the reversed austenite grains. In the specimen without cold rolling, a crystallographic restriction, so-called “austenite memory”, was appeared during the intercritical annealing at 923 K, so that the austenite with the same orientation (same variant) as the prior austenite grains nucleated and grew. In addition, these austenite grains coalesced with each other after annealing at 973 K in the austenite single phase region, leading to the coarse austenite grains of 50 μm (almost the same as that of the prior austenite). In contrast, in the cold-rolled specimen, the extremely fine austenite grains of below 5 μm were formed after annealing at 973 K. This would be because the cold rolling suppressed the strict variant selection owing to the reduction of anisotropic internal local residual stress in martensite, and this prevented the austenite memory. Furthermore, the orientation rotation of the martensite due to the cold rolling had dispersed the orientations of the resulting reversed austenite grains, which is considered to be one of the factors that suppressed the formation of coarse grains.

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Publisher：28th IFHTSE 2023 Congress  

Since type 316L austenitic stainless steel shows great ductility and elongation even at low temperature, it is often used in the cryogenic environment as structural materials such as liquid hydrogen's storage or conducting magnets in nuclear fusion reactor. In order to enhance the strength of type 316L steel, the grain refinement has been considered. It is well known that the yield stress of polycrystalline metallic materials follows the Hall-Petch relationship (σy=σ0+kyd -12), where σy is the yield stress, σ0 is the friction stress, ky is the Hall-Petch coefficient, and d is the mean grain size. In our previous research, we found that nitrogen addition increases ky of austenitic steel at ambient temperature. In this study, we focused on the temperature dependence of Hall-Petch coefficient, ky, to utilize the grain refinement strengthening at low temperature in austenitic stainless steels containing nitrogen, and then the effect of nitrogen content on the ky was discussed. As a result, not only the σ0 is increased by the stronger Cottrell-atmosphere which enhanced by the solid solution nitrogen atoms but also the ky increased with the addition of nitrogen at a temperature range of 293-77 K, and the increase in grain refinement strengthening caused by nitrogen was greatly enhanced at low-temperature. This result suggests that the combined use of nitrogen addition and grain refining was extremely effective for strengthening austenitic steel at low temperature.

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Publisher：28th IFHTSE 2023 Congress  

The dislocation density of lath α'-martensite, with the same Ms temperature and different C content, was evaluated by using the modified Williamson-Hall/Warren-Averbach (mWH/WA) method. Subsequently, the effect of carbon on the dislocation density of lath α'-martensite was clarified. Fe-18Ni, Fe-13.5Ni-0.13C, Fe-9Ni-0.26C, and Fe-0.55C alloys (mass%) were prepared. The Ni content of the alloys was adjusted to ensure that the Ms temperatures of the alloys were identical. The specimens were solution-treated at 1173 K for 1.8 ks, followed by water quenching to obtain the as-quenched α'-martensite structure. Then, some specimens were tempered at 573 K for 16.2 ks (tempered α'). Subsequently, the dislocation density was calculated using line profile analysis (mWH/WA method). In all the specimens, Ms temperatures were in the range of 550-600 K. In the as-quenched specimen, the dislocation density was overestimated due to tetragonality, and thus it is referred to as “apparent dislocation density”. The overestimation of dislocation density increased with increasing carbon content and tetragonality. In tempered specimens, wherein the true dislocation density was obtained by removing the tetragonality, the dislocation density increased with carbon content even in the specimens with the same degree of auto-tempering. Additionaly, it was clarified that the dislocation density was almost saturated at 4-5 × 1015/m-2 at a varbon content exceeding 0.15%.

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Publisher：28th IFHTSE 2023 Congress  

The effect of aluminum on the Ms temperature and microstructure of martensite was investigated in medium carbon steels with and without aluminum. The dilatometry test revealed that the Ms temperatures of 0 mass% and 2 mass% aluminum steels were estimated to be 568 and 638 K, respectively, and increased as the addition of aluminum. Although both steels comprise lath martensite structures, some blocks near the prior austenite grain boundary in 2 mass% aluminum steel are coarser than others. The Vickers hardness of 0 mass% and 2 mass% aluminum steels are 754 and 718 HV, respectively: the hardness decreases with the addition of aluminum. The 200 diffraction peaks in as-quenched 0 mass% and 2 mass% aluminum steel indicate that the solute carbon in martensite matrix decreases with promoting auto-tempering owing to increasing the Ms temperature. In conclusion, the formation of coarse blocks and the reduction of the solute carbon, which are due to the increase of Ms temperature, leads to the decreasing of hardness in aluminum-added steel.

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Language：Japanese   Publisher：The Japan Society for Heat Treatment  

<p>The effect of carbon on the heterogeneous deformation behavior of a martensite was investigated by multiscale strain distribution analysis using the digital image correlation method. Specially, 18％Ni martensitic steels with and without carbon（0.15C steel and C-free steel, respectively）were studied. Low-magnification observation showed that in both steels, a macroscopic strain distribution was caused by the shape of the specimen. However, high-magnification observation revealed that the strain was concentrated in specific blocks in 0.15C steel, suggesting that its heterogeneous deformation behavior depends on the martensitic structure. Thus, addition of carbon in 18％Ni steel was concluded to cause preferential plastic deformation of the blocks owing to an in-lath plane slip system, which tends to promote heterogeneous deformation.</p>

DOI： 10.14940/netsushori.63.192

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Iron and Steel Institute of Japan  

<p>Stress relaxation tests were conducted in the elastic region of an ultralow carbon martensitic steel (Fe–18%Ni alloy) to quantitatively analyze the effect of mobile dislocations on the low elastic limit of the steel. The elastic limit of the as-quenched material was measured at 255 MPa, although its tensile strength was as high as 720 MPa. The stress relaxation tests, which were performed at 255 MPa, revealed a remarkable stress reduction due to the movement of the mobile dislocations present in the as-quenched material. The total dislocation density barely changed during the test, while the distribution parameter (M-value) decreased significantly, indicating that the mobile dislocations exhibited stable arrangements. The 5% cold rolling before the relaxation tests suppressed the relaxation and simultaneously increased the elastic limit to a maximum, 435 MPa. By estimating the mobile dislocation density by relating the stress reduction in the stress relaxation tests to the distance of the dislocation movement evaluated via transmission electron microscopy (TEM) observations, it was estimated that the mobile dislocation density of the 5%-cold-rolled material was lowered to ~1/10 of that of the as-quenched material.</p>

DOI： 10.2355/isijinternational.isijint-2022-196

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DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2022-196

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DOI： https://doi.org/10.1016/j.scriptamat.2022.114791

Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

The relationship of solid solution carbon and electrical resistivity in retained austenite was investigated by using as-quenched martensitic specimens of Fe-10mass%Ni alloys with added carbon up to 0.9 mass%. With increasing carbon content, the volume fraction of retained austenite increased, and simultaneously, the electrical resistivity of the bulk specimen also increased. Four-types of multi-phase models were applied to evaluate the electrical resistivity of each phase. As a result, the electrical resistivity of retained austenite was found to be increased with the increment of solute carbon concentration monotonously. The dependence of the solute carbon concentration (Csol) on the electrical resistivity of retained austenite (Δργ) could be formulated as Δργ [mΩ•mm] = 0.26 × Csol [mass%].

DOI： 10.1016/j.scriptamat.2022.114791

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Publishing type：Research paper (scientific journal)   Publisher：Acta Materialia  

The crystal structure of as-quenched martensite in steel changes from body-centered cubic to body-centered tetragonal because of the presence of interstitial carbon, and the c/a ratio increases with increasing carbon content. Because the X-ray diffraction peak profiles associated with the c-axis overlap those of the a-axis, the diffraction peak observed in martensite gradually broadens as the solute carbon increases. This may cause an overestimation of the dislocation density in the X-ray line profile analysis (for example, modified Williamson-Hall/Warren-Averbach method). In this study, the effect of the tetragonality of martensite in the X-ray line profile analysis was investigated to evaluate the dislocation density in a medium-carbon martensitic steel. The apparent dislocation density estimated without considering peak broadening due to tetragonality was calculated to be 1.7 × 1016 m−2 in the as-quenched 0.55%C steel. This value is approximately six times higher than that estimated using transmission electron microscopy (TEM), indicating that the dislocation density was overestimated. To eliminate the effect of tetragonality, the specimens were tempered at temperatures below 623 K. The estimation based on the TEM method revealed that the dislocation density only slightly decreased by tempering at 573 K, indicating negligible recovery at this temperature. The dislocation density obtained in the tempered specimen was calculated to be approximately 4.5 × 1015 m−2 using the mWH/WA method. This value was regarded as the true dislocation density of the as-quenched martensite in the 0.55%C steel.

DOI： 10.1016/j.actamat.2022.118052

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DOI： https://doi.org/10.1002/srin.202200428

Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.1016/j.actamat.2022.118052

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2021-123

Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

DOI： 10.1299/jsmemag.125.1239_20

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Japan Institute of Metals and Materials  

<p>Age hardening in stable austenitic stainless steel wires with a chemical composition of Fe–18%Cr–12%Ni and different N contents was investigated to clarify the role of N. Age hardening could be enhanced by increasing the drawing ratio and N content. The highest age-hardening effect was observed at 800 K in the N-bearing specimens. In addition, severe drawing induced low-temperature age hardening at 450–600 K. Differential scanning calorimetry (DSC) analysis revealed that age hardening at 800 K may be attributed to particle dispersion strengthening by Cr₂N. Meanwhile, the exothermic peaks observed at 450–600 K were controlled by the pipe diffusion of N. However, nitride precipitates and clusters could not be detected by 3D atom probe analysis, which implies the formation of atomic-scale N products, such as I-S pairs, at the dislocations.</p><p> </p><p>This Paper was Originally Published in Japanese in J. Jpn. Soc. Heat Treat. <b>61</b> (2021) 112–118. Result and Discussion are slightly modified.</p>

DOI： 10.2320/matertrans.mt-h2021001

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DOI： https://doi.org/10.2320/matertrans.MT-H2021001

Language：English   Publisher：The Iron and Steel Institute of Japan  

<p>Neutron transmission spectra of Fe-2 mass% Cu alloy (Cu steel) were measured to characterize the changes of crystallographic texture of ferrite grains and nanostructure of dispersed Cu particles with cold rolling. Bragg edges appearing in the neutron attenuation coefficient of as-aged Cu steel show a sawteeth pattern corresponding to random texture. With increasing equivalent strain, the 110 Bragg edge changes to a peak and the 200 Bragg edge becomes sharp. These changes indicate the rotation of {110} planes toward a tilt angle of 32° to the rolling plane and the increase in the fraction of the {100} planes in the rolling plane. This can be explained by the evolution of <111>//ND, <322>//ND, and <100>//ND preferred orientations with the cold rolling, where ND denotes the normal direction. In the wavelength range longer than 0.4 nm, the neutron attenuation coefficient increases due to a small-angle neutron scattering (SANS) contribution from dispersed Cu particles in the matrix. Comparing the experimental results with simulation, the change in the SANS contribution indicates that the dispersed Cu particles are elongated with the cold rolling. These results demonstrate that the neutron transmission analysis is useful for microstructural characterization of steels and the sequential change of the microstructures.</p>

DOI： 10.2355/isijinternational.isijint-2021-144

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Iron and Steel Institute of Japan  

<p>The concentrations of C and N segregated at the grain boundaries (GB) in Fe–C, Fe–N binary alloys, and Fe–C–N ternary alloys were calculated using the McLean and the Hillert-Ohtani models. Comparison of the calculated data with experimental values obtained by three-dimensional atom probe tomography (3DAP) revealed that the experimental values were roughly explained by the Hillert-Ohtani model for the binary alloys. The McLean model also can predict similar results when the fraction of available sites in the GB layer is assumed to be saturated at 0.1. On the other hand, the Hall-Petch coefficient (<i>k_y</i>) of Fe–C–N, determined from tensile tests, was linearly related to the predicted concentrations of segregated C and N. Proposedly, <i>k_y</i> can be predicted from the chemical composition and heat treatment temperature via thermodynamic calculations.</p>

DOI： 10.2355/isijinternational.isijint-2021-386

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DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2021-386

Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2021-144

Publishing type：Research paper (scientific journal)   Publisher：Oxford University Press (OUP)  

Abstract

Current greenhouse gas emissions suggest that keeping global temperature increase below 1.5 degrees, as espoused in the Paris Agreements will be challenging, and to do so, the achievement of carbon neutrality is of utmost importance. It is also clear that no single solution can meet the carbon neutral challenge, so it is essential for scientific research to cover a broad range of technologies and initiatives which will enable the realization of a carbon free 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, bio-mimetic catalysts, electrochemistry, thermal energy and absorption, carbon capture, storage and management and refrigerants. Here we outline the state of the art for this suite of technologies and detail how their deployment, alongside prudent energy policy implementation can engender a carbon neutral Japan by 2050. Recognizing that just as no single technological solution will engender carbon neutrality, no single nation can expect to achieve this goal alone. This study represents a recognition of conducive international policy agendas and is representative of interdisciplinary, international collaboration.

DOI： 10.1246/bcsj.20210323

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Iron and Steel Institute of Japan  

<p>Medium manganese steel (Fe-5.0%Mn-1.2%Si-0.10%C alloy) was subjected to interrupted quenching from the austenite single-phase region to a temperature between M_s and M_f followed by intercritical annealing in the ferrite and austenite dual-phase region at 923 K. As a result, a core-shell type second phase, which consisted of a fresh martensite core surrounded by a film-like retained austenite shell, was formed. The mechanism and kinetics of reversion for the interrupted-quenched specimens were analyzed with DICTRA simulation and TEM observation. With regard to the effect of the core-shell type second phase on mechanical properties, it was inferred that the fresh martensite core functioned as a hard second phase and enhanced work hardening by stress partitioning similar to DP steel, while the film-like retained austenite contributed to improved ductility due to the TRIP effect. As the interrupted quenching temperature decreased, the volume fraction of the fresh martensite core decreased, while the stability of the retained austenite shell increased. This showed potential for controlling the strength and ductility balance of medium manganese steel. A possible beneficial effect of the core-shell type second phase on the ductile fracture behavior was also discussed in terms of stress/strain relaxation at the interfaces between hard martensite and ferrite matrix.</p>

DOI： 10.2355/tetsutohagane.tetsu-2021-123

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Publisher：Minerals, Metals and Materials Series  

It is expected that high-temperature hydrogen technologies, such as the solid oxide fuel cell and high-temperature water electrolysis, will play important roles in the hydrogen society. In this study, creep tests of JIS SUS304, SUS304L and SUS310S austenitic stainless steels and SUY-1 pure iron were carried out in hydrogen and argon at 873 K. For all the materials, the creep rate in the secondary creep region in hydrogen environment was increased. It resulted in reduction of the creep life. In argon, the fracture surface of the SUS304 changed from dimple to intergranular fracture with the increase in the creep life. In hydrogen, this change was delayed. Regarding the mechanism, it was confirmed that the effect of carbide formation, HELP and HTHA were not activated in this study. Instead, enhanced dislocation climb mediated by an increased vacancy density is a plausible mechanism, although further investigation is needed.

DOI： 10.1007/978-3-030-92381-5_146

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Scopus

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DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2020-669

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DOI： https://doi.org/10.1016/j.msea.2021.141058

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DOI： https://doi.org/10.1016/j.scriptamat.2020.10.044

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DOI： https://doi.org/10.2472/jsms.70.31

Language：English   Publishing type：Research paper (scientific journal)  

Medium manganese steel (Fe-5.0%Mn-1.2%Si-0.10%C alloy) was subjected to interrupted quenching from the austenite single-phase region to a temperature between Ms and Mf followed by intercritical annealing in the ferrite and austenite dual-phase region at 923 K. As a result, a core-shell type second phase, which consisted of a fresh martensite core surrounded by a film-like retained austenite shell, was formed. The mechanism and kinetics of reversion for the interrupted-quenched specimens were analyzed with DICTRA simulation and TEM observation. With regard to the effect of the core-shell type second phase on mechanical properties, it was inferred that the fresh martensite core functioned as a hard second phase and enhanced work hardening by stress partitioning similar to DP steel, while the film-like retained austenite contributed to improved ductility due to the TRIP effect. As the interrupted quenching temperature decreased, the volume fraction of the fresh martensite core decreased, while the stability of the retained austenite shell increased. This showed potential for controlling the strength and ductility balance of medium manganese steel. A possible beneficial effect of the core-shell type second phase on the ductile fracture behavior was also discussed in terms of stress/strain relaxation at the interfaces between hard martensite and ferrite matrix.

DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2020-164

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2020-011

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DOI： https://doi.org/10.1007/s11661-020-05981-0

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DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2020-049

Language：Japanese   Publishing type：Research paper (scientific journal)  

Electrical resistivity of low-carbon martensitic steels was measured to estimate the carbon concentration in solid solution. Since electrical resistivity is influenced not only by solute carbon but also by substitu-tional elements, lattice defects and second phase, the effects of these factors need to be subtracted from total electrical resistivity, in order to obtain the accurate solute carbon concentration by this method. As a result, the effects of dislocations and grain boundaries were much smaller than that of solute elements, being only 1 - 2% of the measured electrical resistivity, in martensitic steel. On the other hand, substi-tutional elements and retained austenite were found to be significantly effective. By subtracting these effects from the measured value, the change in electrical resistivity due to solute carbon, Δρsol.C, could be formulated as a function of the carbon concentration in solid solution of martensite, Csol, as follows:
Δρsol.C [mΩmm] = 0.25 × Csol [mass%]
The estimated solute carbon concentration was confirmed to correspond to the directly measured value by atom probe tomography.

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2020-050

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DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2019-129

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DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2019-103

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DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2019-105

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DOI： https://doi.org/10.1016/j.commatsci.2020.109871

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DOI： https://doi.org/10.2472/jsms.69.290

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DOI： https://doi.org/10.1016/j.scriptamat.2019.10.018

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後ほど入力

DOI： https://doi.org/10.1016/j.commatsci.2019.109500

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DOI： https://doi.org/10.2320/matertrans.H-M2020804

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DOI： https://doi.org/10.1016/j.scriptamat.2019.10.018

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DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2019-053

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DOI： https://doi.org/10.1016/j.ijplas.2020.102700

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DOI： https://doi.org/10.1016/j.ijhydene.2020.02.014

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DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2019-062

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DOI： https://doi.org/10.2472/jsms.68.917

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DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2019-009

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DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2018-167

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DOI： https://doi.org/10.1016/j.scriptamat.2019.05.001

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DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2018-623

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DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2018-088

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DOI： https://doi.org/10.1016/j.ijplas.2018.08.006

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DOI： https://doi.org/10.1007/s11661-018-4972-x

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DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2018-404

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DOI： https://doi.org/10.1016/j.ijhydene.2018.11.031

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DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2018-054

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DOI： https://doi.org/10.2472/jsms.67.860

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DOI： https://doi.org/10.1007/s10704-018-0304-9

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DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2018-021

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DOI： https://doi.org/10.1007/978-3-319-76968-4_39

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In order to evaluate the effects of carbon and nitrogen addition on the stability of austenite, athermal and deformation-induced
a0-martensitic transformation behaviors were investigated using type 304-metastable austenitic stainless steels containing 0.1 mass% carbon or
nitrogen. The difference in the development of the deformation microstructure in particular is discussed in terms of the stacking-fault energy
(SFE). Since carbon-added steel has a lower SFE than that of nitrogen-added steel, deformation twins and e-martensite were preferentially formed
in the carbon-added steel, whereas a dislocation cell structure developed in the nitrogen-added steel. Crystallographic analysis using the electron
backscatter diffraction method revealed that the difference in the deformation microstructure has a significant influence on the growth behavior
of deformation-induced a0-martensite, that is, the interface of the deformation twins and e-martensite suppresses the growth of a0-martensite, whereas
dislocation cell boundaries are not effective. As a result, the mechanical stability of carbon-added steel is slightly higher than that of nitrogen-added
steel, although the thermal stabilization effect of carbon is much lower than that of nitrogen.

DOI： 10.1016/j.actamat.2014.10.041

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

The range of chemical compositions that can obtain an austenitic single structure was defined for
medium-manganese (Mn) carbon (C) steels. Among the potential compositions, Fe-5%Mn-4%Cr-(0.8–
1.4)%C (mass%) was selected as the optimized composition range to form a stable austenitic structure.
The tensile properties and deformation substructure were investigated in the austenitic steels having this
composition. The work hardening behavior of the steels varied depending on the carbon content, which
was closely related to the deformation microstructure. In the 0.8%C steel, both a deformation-induced
martensitic phase as well as the formation of deformation twins generated a high work hardening until
fracture. With an increasing carbon content, which increased the stacking fault energy (SFE), the deformation
tended to shift towards dislocation slipping, resulting in a lower work hardening rate. This trend
appears similar to conventional twinning-induced plasticity steel where the work hardening behavior is
tied to the SFE.

Language：English   Publishing type：Research paper (scientific journal)  

In ordertoclarifythethermodynamicsandkineticsofsolutionnitriding,thenon-uniformnitrogen
distribution formedbysolutionnitridingwasinvestigatedinaustenitic(18Cr–10Ni)andferritic(25Cr)
stainless steels,andthenitwassimulatedwith DICTRA. Themainissueforausteniticstainlesssteelisthe
surface reactiondeterminedbythemasstransferfromgastosolid,whilethatforferriticstainlesssteelis
the ferritetoaustenitetransformationandtheaustenitegrowthkineticsinducedbynitrogenabsorption.
DICTRA simulations gavecloseagreementwiththeexperimentalresultsanddemonstratedthatsolution
nitriding isobviouslycontrolledbymasstransferofnitrogenfromgastosolidaswellasdiffusioninthe
solid, andaustenitegrowthiscontrolledbynitrogendiffusioninaustenite.Inaddition,theanalysis
suggests thatnitrogenshouldhaveastrongerinteractionwithchromiumthanthattreatedinthe
thermodynamic databaseandaustenitenucleationinducedbynitrogenabsorptiontakesplacewithout
anychangeinCrcomposition.

DOI： 10.1016/j.calphad.2014.09.006

Language：English   Publishing type：Research paper (scientific journal)  

Solution nitriding was applied to a metastable austenitic stainless steel plate (Fe–18Cr–8Ni alloy) to stabilize the austenite near
the plate surface. After cold rolling, the interior austenite almost entirely transformed to martensite, but the stabilized surface austenite
remained unchanged. The interior deformation-induced martensite contributes to the material’s high strength and the surface
stable austenite-layer plays an important role in preventing hydrogen permeation. As a result, the resistance to hydrogen embrittlement
was significantly improved for the cold-rolled specimen.

DOI： 10.1016/j.scriptamat.2014.07.005

Language：Japanese   Publishing type：Research paper (scientific journal)  

The effect of pearlite on the X-ray diffraction peak reflected
from ferrite phase in ferrite-pearlite steel was investigated
using normalized carbon steels with different volume fraction
of pearlite and a hypereutectoid steel with various
pearlite lamellar spacing. The lattice strain in ferrite phase,
which causes the broadening of X-ray diffraction peak, was
increased in proportion to both of the volume fraction of
pearlite and the inverse of pearlite lamellar spacing. As a
result, the lattice strain in ferrite-pearlite steel can be simply
formulated as functions of them. On the other hand, TEM observation
reveals that pearlite has low-density dislocation in
ferrite phase. This result suggests that the misfit between ferrite
and cementite in pearlite generates the significant amount
of elastic strain, which leads to the increasing in lattice strain.
Therefore, the dislocation density must be overestimated in
carbon steels with pearlite, if it is estimated from the experimental
lattice strain directly.

DOI： http://dx.doi.org/10.2355/tetsutohagane.100.1229

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s10704-013-9895-3

Language：Japanese   Publishing type：Research paper (scientific journal)  

For a better understanding the relation between the heterogeneous microscopic strain caused by metallographic microstructure and the macroscopic
strain concentration responsible for ductile fracture, digital image correlation (DIC) method was applied to the digital images obtained
by a scanning electron microscope (SEM) to analyze a strain distribution in a low carbon dual-phase steel in multiple scales. As well as grain
boundaries, a substructure in martensite grains and a corrosion shade in ferrite matrix were clearly observed in SEM image and they enhance
the random nature of SEM digital image. Therefore, the combination of SEM image and DIC method (SEM-DIC method) is able to evaluate a
heterogeneous strain distribution in metal in multiple scales. The development of strain distribution looks different depending on the magnification
of SEM observation due to the difference in pixel-dependent spatial resolution; micro-scale strain map indicated that strain is localized
in ferrite matrix, while macro-scale strain map revealed that strain seems to exist over a width of tensile specimen. This result suggests that
macroscopic strain concentration is accompanied by a percolation of microscopic localized strains. In addition, the strain in martensite grains
is increased considerably as the hardness of martensite is reduced by tempering treatment, which leads to the reduction in the strain gap between
ferrite and martensite. As a result, the developments of not only microscopic localized strain but also macroscopic strain concentration
are retarded, leading to the significant recover of ductility in DP steel.

DOI： http://dx.doi.org/10.2355/tetsutohagane.100.1238

Language：Japanese   Publishing type：Research paper (scientific journal)  

Fe-25Cr-1N-0, 2, 5Mn mass% alloys were subjected to isothermal heat treatment, and their microstructure formation and phase transformation
behavior were investigated in order to clarify the effect of Mn addition on the transformation mechanism of high nitrogen austenite.
Microstructure observation for the 1073 K heat-treated specimens revealed that the Fe-25Cr-1N alloy exhibited (α+Cr2N) lamellar eutectoid
structure, while the Fe-25Cr-1N-2Mn and -5Mn alloys did finer (α’(or retained γ)+Cr2N) lamellar structure as well as (α+Cr2N) lamellar eutectoid
structure. It was suggested that the (α’+Cr2N) lamellar structure had been formed through γ1→γ2+Cr2N cellular precipitation followed
by martensitic transformation of γ2 on cooling to ambient temperature. Nitrogen concentration in untransformed austenite in the Fe-25Cr-1N-
2Mn and -5Mn alloys was continuously decreased with progressing of (γ+Cr2N) cellular precipitation due to nitrogen long-range diffusion
from untransformed austenite to (γ+Cr2N) cellular structure. As a result of decreased nitrogen concentration in untransformed austenite, transformation
mechanism switched from (γ+Cr2N) cellular precipitation to (α+Cr2N) eutectoid transformation.

DOI： http://dx.doi.org/10.2355/tetsutohagane.100.1165

Language：English   Publishing type：Research paper (scientific journal)  

Brittle-to-ductile transition (BDT) in Cu added Ni-free austenitic stainless steel was investigated. Temperature
dependence of apparent fracture toughness was measured using four-point bending tests, indicating
that the BDT temperature was decreased with the increase in the Cu content. The activation energy
was obtained from the deformation rate dependence of BDT temperatures. It was found that the values
of the activation energy was decreased with the increase in the Cu content, suggesting that the dislocation
mobility in austenitic stainless steels was increased by Cu addition. The increase in the dislocation
mobility induces the decrease in the BDT temperature. The values of the activation energy are deviated
from the regression line drawn on the data which obtained from the materials with high Peierls potentials.
Temperature dependence of 0.2% proof stress indicated that the effective stress was nearly independent
from the Cu content while the values of activation volume were decreased with the increase in the Cu
content. A model for dislocation glide was proposed to explain the both decrease in the activation energy
and the activation volume with the increase in the Cu content.

DOI： 10.2355/isijinternational.54.1735

Language：Japanese   Publishing type：Research paper (scientific journal)  

The majority of engineering steels are ferromagnetic and structually inhomogeneous on special scales ranging from nanometers to micrometers,
and physical properties of engineering steels arise from three-dimensional (3D) features of the microstructure. Thus, obtaining 3D representation
with a large field of view is desired for transmission electron microscopy (TEM) based microstructure characterization to establish
microstructure - physical properties relationships with reasonable statistical relevancy. Here, we venture to use a conventional sample preparation
process, i.e., mechanical polishing followed by electro-polishing, and experimental protocols optimization for electron tomography (ET)
for ferromagnetic materials, especially engineering steels’ microstructural characterization are carried out. We found that the sample thickness
after the mechanical polishing step is a critical experimental parameter affecting the success rate of tilt-series image acquisition. For example,
for a ferritic heat-resistant 9Cr steel with lath martensite structure, mechanically thinning down to 30 μm or thinner was necessary to acquire
an adequate tilt-series image of carbide precipitates in the high-angle annular dark-field scanning TEM (HAADF-STEM) mode. On the other
hand, tilt-series image acquisition from dislocation structures remains challenging because the electron beam deflection during specimen-tilt
was unavoidable and significant in the HAADF-STEM mode. To overcome the electron beam deflection problem, we evaluate several relatively
accessible approaches including the “Low-Mag and Lorentz” TEM/STEM modes; although they are rarely used for ET, both the modes
reduce or even zero the objective lens current and likely weaken the magnetic interference between the ferromagnetic specimen and the objective
lens magnetic field. The advantages and disadvantages of those experimental components are discussed.

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

In ordertoclarifytheeffectsofthemartensitedistributiononthemechanicalpropertiesoflow-carbon
dual-phase steel,fourtypesofdual-phasesteelwithdifferentferritegrainsizesandmartensite
distributions werepreparedusingathermomechanicaltreatment.Thetensilepropertiesofthesesteels
wereinvestigated;inparticular,thestrainhardeningandtheductilefracturebehaviorswerediscussed
in termsofthestrainpartitioningbetweentheferriteandmartensiteandtheformationandgrowth
of micro-voids,respectively.Whenthemartensitegrainssurroundtheferritegrainsandformachain-
like networkedstructure,thestrainhardenabilityisgreatlyimprovedwithoutasignificant lossof
elongation, whiletheneckingdeformabilityisconsiderablyreduced.Adigital-imagecorrelationanalysis
revealedthatthetensilestraininthemartensiteregioninthechain-likenetworkeddual-phase
structure ismarkedlyincreasedduringtensiledeformation,whichleadstoanimprovementinthestrain
hardenability.Ontheotherhand,thejointpartofthemartensitegrainsinthestructureactsasa
preferentialformationsiteformicro-voids.Thenumberdensityofthemicro-voidsrapidlyincreases
with increasingtensilestrain,whichwouldcausethelowerneckingdeformability.

Language：English   Publishing type：Research paper (scientific journal)  

Interstitial-free steels containing 1–3% Ni were tensile tested. A clear yield point and yield point elongation were observed in each
steel, even though they contained no solute carbon or nitrogen in the ferrite matrix. The mechanism could be explained by grain
refinement strengthening enhanced by the addition of Ni, which is derived from the increase in Hall–Petch coefficient caused by
grain boundary segregation.

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.actamat.2013.10.067

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DOI： 10.2320/matertrans.MA201314

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DOI： 10.2355/isijinternational.53.2275

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DOI： 10.2355/isijinternational.53.1286

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DOI： 10.2355/isijinternational.53.1224

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DOI： 10.2355/isijinternational.53.139

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Language：Japanese   Publishing type：Research paper (other academic)  

Difference in Recrystallization Behavior between Martensite and Deformed Ferrite
Y. FUTAMURA M. NATORI T. TSUCHIYAMA and S. TAKAKI
Materials Science Forum Vols. 467-470 (ReX and GG II)
Vol. (2004)pp.263-268.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Initial Microstructure on Superplasticity in Ultrafine Grained 18Cr-9Ni Stainless Steel
T. TSUCHIYAMA Y. NAKAMURA H. HIDAKA and S. TAKAKI
Materials Transactions
Vol.45 7(2004)pp.2259-2263.

DOI： 10.2320/matertrans.45.2259

Language：Japanese   Publishing type：Research paper (other academic)  

Effect of Initial Microstructure on Recrystallization Behavior during Annealing
M. NATORI Y. FUTAMURA T. TSUCHIYAMA and S. TAKAKI
Proceedings of 8th Ultra-Steel Workshop
Vol. (2004)pp.222-223.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Grain Refinement on Thermal Stability of Metastable Austenitic Steel
S. TAKAKI K. FUKUNAGA J. SYARIF and T. TSUCHIYAMA
Materials Transactions
Vol.45 7(2004)pp.2245-2251.

DOI： 10.2320/matertrans.45.2245

Language：Japanese   Publishing type：Research paper (other academic)  

Importance of Size-Distribution of Dispersed Particles in Particle Dispersion Strengthening
T. KITAURA H. HIDAKA T. TSUCHIYAMA and S. TAKAKI
Proceedings of International Symposium on Ultrafine Grained Steels (ISUGS 2003)
Vol.CD-ROM (2003)pp.-.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Precipitation Strengthening at Elevated Temperature in Fe-Cu Alloys
K. NAKASHIMA Y. FUTAMURA T. TSUCHIYMA and S. TAKAKI
Tetsu-to-Hagane
Vol.89 5(2003)pp.524-529.

Language：English   Publishing type：Research paper (scientific journal)  

Mechanism of Toughening in Ferritic Iron by Solute Copper at Low Temperature
J. SYARIF T. TSUCHIYAMA and S. TAKAKI
ISIJ International
Vol.43 7(2003)pp.1100-1104.

DOI： 10.2355/isijinternational.43.1100

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Boron Recrystallization Behavior in Ultra-Low Carbon Martensitic Steel
Y. FUTAMURA T. KAWAMURA T. TSUCHIYAMA and S. TAKAKI
Tetsu-to-Hagane
Vol.80 3(2003)pp.335-341.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Cu Addition on Formation of Reversed Austenite and Hardness in 9%Ni steels
N. NAKADA T. YAMASHITA J. SYARIF T. TSUCHIYAMA and S. TAKAKI
Tetsu-to-Hagane
Vol.89 10(2003)pp.1050-1056.

Language：English   Publishing type：Research paper (other academic)  

Temperature Dependence of Hall-Petch Relationship in Ultra Fine Grained Iron
K. KAWASAKI T. TSUCHIYAMA and S.TAKAKI
Proceedings of International Symposium on Ultrafine Grained Steels (ISUGS 2003)
Vol.CD-ROM (2003)pp.-.

Language：English   Publishing type：Research paper (other academic)  

Bailey-Hirsch Relationship in Deformed Iron and Martensitic Steels
M. SUZUKI K. NAKASHIMA Y. FUTAMURA S. JUNAIDI T. TSUCHIYAMA and S. TAKAKI
Proceedings of International Symposium on Ultrafine Grained Steels (ISUGS 2003)
Vol.CD-ROM (2003)pp.-.

Language：English   Publishing type：Research paper (other academic)  

Effect of Copper Particles on Softening Behavior During Tempering in 9% Nickel Martensitic Steels
S. NAKADA S. JUNAIDI T. TSUCHIYAMA and S. TAKAKI
Proceedings of International Symposium on Ultrafine Grained Steels (ISUGS 2003)
Vol.CD-ROM (2003)pp.-.

Language：English   Publishing type：Research paper (other academic)  

Effect of Grain Refinement on Thermal Stability of Metastable Austenite
S. TAKAKI K. FUKUNAGA and T. TSUCHIYAMA
Proceedings of International Symposium on Ultrafine Grained Steels (ISUGS 2003)
Vol.CD-ROM (2003)pp.-.

DOI： 10.2320/matertrans.45.2245

Language：Japanese   Publishing type：Research paper (scientific journal)  

Grain Size Control by Oxide Dispersion in Austenitic Stainless Steel
K. TAKANO R. NAKAO N. FUKUMOTO T. TSUCHIYAMA and S. TAKAKI
Tetsu-to-Hagane
Vol.89 5(2003)pp.616-622.

Language：English   Publishing type：Research paper (other academic)  

Superplasticity of Austenitic Stainless Steel Containing Thermally Unstable Martensite Particles
T. TSUCHIYAMA Y. NAKAMURA H. HIDAKA and S. TAKAKI
Proceedings of International Symposium on Ultrafine Grained Steels (ISUGS 2003)
Vol.CD-ROM (2003)pp.-.

Language：English   Publishing type：Research paper (other academic)  

Ostwald Ripening Behavior of Cu Particles in Martensitic Steels
Y. FUTAMURA T. TSUCHIYAMA and S. TAKAKI
Proceedings of International Symposium on Ultrafine Grained Steels (ISUGS 2003)
Vol.CD-ROM (2003)pp.-.

Language：English   Publishing type：Research paper (scientific journal)  

Fabrication of Ultrahigh Nitrogen Austenitic Steels by Nitrogen Gas Absorption into Solid Solution
T. TSUCHIYAMA H. ITO K. KATAOKA and S. TAKAKI
Metallurgical and Materials Transactions A
Vol.34A 11(2003)pp.2591-2599.

DOI： 10.1007/s11661-003-0018-z

Language：English   Publishing type：Research paper (other academic)  

Thermodynamics of Nitrogen Absorption into Solid Solution in Fe-Cr-Mn Ternary Alloys
T. TSUCHIYAMA and S. TAKAKI
Materials Science Forum Vols. 426-432
Vol.2 (2003)pp.957-962.

Language：English   Publishing type：Research paper (other academic)  

Microstructural Change during Mechanical Milling Treatment in Fe-C Alloy Powders with Different Initial Microstructure
H. HIDAKA T. TSUCHIYAMA and S. TAKAKI
Materials Science Forum Vols. 426-432
Vol.3 (2003)pp.2717-2722.

Language：English   Publishing type：Research paper (scientific journal)  

Effect of Carbon on Nano-Crystallization in Steel during Mechanical Milling Treatment
H. HIDAKA K. KAWASAKI T. TSUCHIYAMA and S. TAKAKI
Materials Transactions
Vol.44 10(2003)pp.1912-1918.

DOI： 10.2320/matertrans.44.1912

Language：Japanese   Publishing type：Research paper (scientific journal)  

Formation of TiB Particles during Reaction Sintering in a TiB/Ti Composite
T. YOSHIHIRO T. TSUCHIYAMA and S. TAKAKI
Journal of the Japan Institute of Metals
Vol.67 7(2003)pp.362-367.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effects of Prior Deformation on Dispersion of Carbide Precipitates during Isothermal Transformation in 12%Cr-0.1%C Steel
K. TAKANO T. TSUCHIYAMA and S. TAKAKI
Tetsu-to-Hagane
Vol.88 11(2002)pp.779-785.

Language：English   Publishing type：Research paper (other academic)  

Fabrication of Fine-Grained High Nitrogen Austenitic Steels through Mechanical Alloying Treatment
T. TSUCHIYAMA H. UCHIDA K. KATAOKA and S. TAKAKI
Proceedings of First International Conference on Advanced Structural Steels (ICASS 2002)
Vol. (2002)pp.57-58.

Language：English   Publishing type：Research paper (scientific journal)  

Fabrication of Fine-Grained High Nitrogen Austenitic Steels through Mechanical Alloying Treatment　
T. TSUCHIYAMA H. UCHIDA K. KATAOKA and S. TAKAKI
ISIJ International
Vol.42 12(2002)pp.1438-1443.

DOI： 10.2355/isijinternational.42.1438

Language：English   Publishing type：Research paper (other academic)  

Embrittlement in Copper Bearing Heat Resistant Martensitic Steels
Y. FUTAMURA T. TSUCHIYAMA and S. TAKAKI
Proceedings of First International Conference on Advanced Structural Steels (ICASS 2002)
Vol. (2002)pp.201-202.

Language：English   Publishing type：Research paper (scientific journal)  

Interaction between Dislocation and Copper Particles in Fe-Cu Alloys　
K. NAKASHIMA Y. FUTAMURA T. TSUCHIYAMA and S. TAKAKI
ISIJ International
Vol.42 12(2002)pp.1541-1545.

DOI： 10.2355/isijinternational.42.1541

Language：English   Publishing type：Research paper (other academic)  

Effect of Oxide Addition on Thermal Stability of Ultra Fine-Grained Structure in Iron
H. HIDAKA T. TSUCHIYAMA and S. TAKAKI
Proceedings of First International Conference on Advanced Structural Steels (ICASS 2002)
Vol. (2002)pp.59-60.

Language：English   Publishing type：Research paper (other academic)  

Interaction between Dislocation and Copper Particles in Fe-Cu Alloys
K. NAKASHIMA Y. FUTAMURA T. TSUCHIYAMA and S. TAKAKI
Proceedings of First International Conference on Advanced Structural Steels (ICASS 2002)
Vol. (2002)pp.177-178.

Language：English   Publishing type：Research paper (scientific journal)  

Relation between Microstructure and Hardness in Fe-C Alloys with Ultra Fine Grained Structure
H. HIDAKA T. TSUCHIYAMA and S. TAKAKI
Scripta Materialia
Vol.44 8/9(2001)pp.1503-1506.

DOI： 10.1016/S1359-6462(01)00714-X

Language：English   Publishing type：Research paper (other academic)  

Transformation Behavior Controlled by Fine Oxide Particles in Fine-Grained Eutectoid Steel
K. KASUYA H. HIDAKA T. TSUCHIYAMA and S. TAKAKI
Proceedings of International Symposium on Ultrafine Grained Steels (ISUGS 2001)
Vol. (2001)pp.202-205.

Language：English   Publishing type：Research paper (other academic)  

Temperature Dependence of Deformation Behavior in Ultra Fine-Grained Iron
K. KAWASAKI H. HIDAKA T. TSUCHIYAMA and S. TAKAKI
Proceedings of International Symposium on Ultrafine Grained Steels (ISUGS 2001)
Vol. (2001)pp.244-247.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Microstructure and Mechanical Properties of Fine-Grained High Nitrogen Steels Fabricated through Mechanical Alloying Treatment
H. UCHIDA K. KATAOKA T. TSUCHIYAMA H. GOTO and S. TAKAKI
Journal of the Japan Society of Powder and Powder Metallurgy
Vol.48 10(2001)pp.980-985.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Isothermal Transformation Behavior in 12%Cr-0.3%C Steel
M. MIKAMI T. TSUCHIYAMA and S. TAKAKI
Tetsu-to-Hagane
Vol.87 1(2001)pp.49-54.

Language：English   Publishing type：Research paper (other academic)  

Mechanism of Grain Refining of Austenite by Copper Addition in 8mass%Ni Martensitic Steel
J. SYARIF T. TSUCHIYAMA and S. TAKAKI
Proceedings of the Fourth Pacific Rim International Conference on Advanced Materials and Processing (PRICM4)
Vol. (2001)pp.1955-1958.

Language：English   Publishing type：Research paper (other academic)  

Fabrication of a High Nitrogen Atainless Steel by Powder Metallurgy Process through Mechanical Milling Treatment
K. KATAOKA T. TSUCHIYAMA H. GOTO and S. TAKAKI
Proceedings of International Conference on Processing and Manufacturing of Advanced Materials (THERMEC 2000)
Vol. (2001)pp.CD ROM B1-4.

Language：English   Publishing type：Research paper (other academic)  

Microstructure and Mechanical Properties of Fine-Grained High Nitrogen Stainless Steels Fabricated through Mechanical Alloying Treatment
H. UCHIDA H. HIDAKA T. TSUCHIYAMA and S. TAKAKI
Proceedings of International Symposium on Ultrafine Grained Steels (ISUGS 2001)
Vol. (2001)pp.298-301.

Language：English   Publishing type：Research paper (scientific journal)  

Recrystallization of Lath Martensite with Bulge Nucleation and Growth Mechanism
T. TSUCHIYAMA Y. MIYAMOTO and S. TAKAKI
ISIJ International
Vol.41 9(2001)pp.1047-1052.

DOI： 10.2355/isijinternational.41.1047

Language：English   Publishing type：Research paper (scientific journal)  

Strengthening Mechanism of Cu bearing Heat Resistant Martensitic Steels
Y. FUTAMURA T. TSUCHIYAMA and S. TAKAKI
ISIJ International (Supplement)
Vol.41 0(2001)pp.S106-S110.

DOI： 10.2355/isijinternational.41.Suppl_S106

Language：Japanese   Publishing type：Research paper (scientific journal)  

Microstructure Control and Superplasticity of Sintered Ti-4%Cr-Al Alloy
S. HIRONAKA T. TSUCHIYAMA and S. TAKAKI
Journal of the Japan Society of Powder and Powder Metallurgy
Vol.48 1(2001)pp.39-44.

Language：English   Publishing type：Research paper (other academic)  

Effect of Solute Copper on Grain Growth of Austenite in High Chromium Steels
Y. FUTAMURA T. TSUCHIYAMA and S. TAKAKI
Recrystallization and Grain Growth
Vol.1 (2001)pp.367-372.

Language：English   Publishing type：Research paper (other academic)  

Recrystallization Mechanism of Lath Martensite in High Chromium Steel
T. TSUCHIYAMA and S. TAKAKI
Recrystallization and Grain Growth
Vol.2 (2001)pp.803-808.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Isothermal Transformation Behavior in 12%Cr-0.3%C Steel with Partial Solution Treatment
H. INABA M. MIKAMI Y. ONO T. TSUCHIYAMA and S. TAKAKI
Tetsu-to-Hagane
Vol.87 9(2001)pp.613-618.

Language：English   Publishing type：Research paper (other academic)  

Embrittlement through Cu addition and Its Improvement in Heat Resistant Martensitic Steels
Y. FUTAMURA T. TSUCHIYMA and S. TAKAKI
Proceedings of International Conference on Processing and Manufacturing of Advanced Materials (THERMEC 2000)
Vol. (2001)pp.CD ROM C1-7.

Language：English   Publishing type：Research paper (scientific journal)  

Microstructure Control for Toughening a High Carbon Martensitic Stainless Steel
T. TSUCHIYAMA Y. ONO and S. TAKAKI
ISIJ International (Supplement)
Vol.40 0(2000)pp.S184-S188.

Language：English   Publishing type：Research paper (other academic)  

Strengthening Mechanisms in Heat-Resistant Martensitic 9Cr Steels
K. IWANAGA T. TSUCHIYAMA and S. TAKAKI
Key Engineering Materials Vols. 171-174 (Creep and Fracture of Engineering Materials and Structures)
Vol.0 0(2000)pp.477-482.

Language：English   Publishing type：Research paper (other academic)  

Effect of Solute Copper on Low Temperature Toughness in α-Iron
J. SYARIF T. HOSHINO T. TSUCHIYAMA and S. TAKAKI
Proceedings of the 10th Iketani Conference on Materials Research Toward 21st Century
Vol.0 0(2000)pp.117-118.

Language：English   Publishing type：Research paper (other academic)  

Strengthening of Heat Resistant Steel by Cu Addition
T. TSUCHIYAMA Y. FUTAMURA and S. TAKAKI
Key Engineering Materials Vols. 171-174 (Creep and Fracture of Engineering Materials and Structures)
Vol.0 0(2000)pp.411-418.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Solute Copper on Hardness and Ductile-to-Brittle Transition in α-Iron
J. SYARIF T. HOSHINO T. TSUCHIYAMA and S. TAKAKI
Tetsu-to-Hagane
Vol.86 8(2000)pp.558-562.

Language：English   Publishing type：Research paper (other academic)  

Contribution of Oxide Particles to Thermal Stability of Ultra Fine-Grained Structure
H. HIDAKA S. NAKAMYO T. TSUCHIYAMA and S. TAKAKI
Proceedings of 1st International Conference on Advanced Materials Processing
Vol.0 0(2000)pp.601-606.

Language：English   Publishing type：Research paper (other academic)  

Effect of Solute Alloying Elements on Creep Deformation Behavior in High Cr Martensitic Steels
K. IWANAGA T. TSUCHIYAMA and S. TAKAKI
Proceedings of STAINLESS STEEL99 SCIENCE AND MARKET
Vol.2 0(1999)pp.447-452.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Cu addition on Phase Transformation in 9mass%Cr Martensitic Steels
Y. FUTAMURA T. TSUCHIYAMA and S. TAKAKI
Tetsu-to-Hagane
Vol.85 9(1999)pp.697-702.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Fabrication of Stainless Steels with Composit Structure by Nitrogen Gas Atmosphere Sintering
K. KATAOKA N. NAKAMURA T. TSUCHIYAMA H. GOTO and S. TAKAKI
Journal of the Japan Society of Powder and Powder Metallurgy
Vol.46 11(1999)pp.1136-1140.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Fabrication of High Nitrogen Austenitic Stainless Steels by Powder Metallurgy
K. KATAOKA T. TSUCHIYAMA H. GOTO and S. TAKAKI
Journal of the Japan Society of Powder and Powder Metallurgy
Vol.46 11(1999)pp.1249-1255.

Language：English   Publishing type：Research paper (other academic)  

Effect of Structural Factors on the Mechanical Properties of High Nitrogen Austenitic Steel
N. NAKAMURA T. TSUCHIYAMA and S. TAKAKI
Materials Science Forum Vols. 318-320 (High Nitrogen Steels)
Vol.0 0(1999)pp.209-214.

Language：English   Publishing type：Research paper (other academic)  

Effect of Ni addition on Softening Behavior During Tempering in Martensitic Stainless Steels
T. TSUCHIYAMA and S. TAKAKI
Proceedings of STAINLESS STEEL99 SCIENCE AND MARKET
Vol.2 0(1999)pp.127-135.

Language：English   Publishing type：Research paper (other academic)  

Superplasticity of Sintered Titanium Alloy with Martensitic Structure
K. OKAZAKI T. TSUCHIYAMA N. Nakamura and S. TAKAKI
Materials Science Forum Vols. 304-306 (Towards Innovation in Superplasticity II)
Vol.0 0(1999)pp.121-126.

Language：English   Publishing type：Research paper (other academic)  

Variants of M23C6 Type Carbide Precipitate in Deformed High Chromium Martensitic Steel
T. TSUCHIYAMA and S. TAKAKI
Solid-Solid Phase Transformations II
Vol.0 0(1999)pp.1613-1616.

Language：English   Publishing type：Research paper (scientific journal)  

Effect of Partial SolutionTreatment on Toughness of 12%Cr-0.3%C Steels
T. TSUCHIYAMA and S. TAKAKI
ISIJ International
Vol.39 2(1999)pp.202-208.

DOI： 10.2355/isijinternational.39.202

Language：English   Publishing type：Research paper (other academic)  

Microstructure and Strengthening Mechanism of Cu Bearing High Cr Martensitic Steels
Y. FUTAMURA T. TSUCHIYAMA and S. TAKAKI
Solid-Solid Phase Transformations II
Vol.0 0(1999)pp.1601-1604.

Language：English   Publishing type：Research paper (other academic)  

Reversion from Eutectoid Structure to Austenite in High Manganese Austenitic Steels
Y. ONO T. TSUCHIYAMA and S. TAKAKI
Solid-Solid Phase Transformations II
Vol.0 0(1999)pp.1641-1644.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Microstructural Change during Isothermal Aging in High Manganese Austenitic Steels
Y. ONO T. TSUCHIYAMA and S. TAKAKI
Tetsu-to-Hagane
Vol.84 4(1998)pp.309-314.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Relationship between Creep Behavior and Microstructure in Martensitic Heat Resistant Steel
K. IWANAGA T. TSUCHIYAMA and S. TAKAKI
Tetsu-to-Hagane
Vol.84 12(1998)pp.896-901.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Phase Transformation Mechanism of Ferritic Stainless Steel by Nitrogen Absorption
N. NAKAMURA T. TSUCHIYAMA and S. TAKAKI
Tetsu-to-Hagane
Vol.84 6(1998)pp.441-445.

Language：English   Publishing type：Research paper (other academic)  

Formation of Reversed Austenite from M23C6 Type Carbide in High Chromium Martensitic Steel
T. TSUCHIYAMA and S. TAKAKI
Proceedings of the Third Pacific Rim International Conference on Advanced Materials and Processing (PRICM3)
Vol.1 0(1998)pp.1187-1192.

Language：English   Publishing type：Research paper (other academic)  

Microstructure Control of a High Carbon Martensitic Stainless Steel by Partial Solution Treatment
T. TSUCHIYAMA and S. TAKAKI
Proceedings of International Conference on Thermomechanical Processing of Steels & Other Materials (THERMEC97)
Vol.2 0(1997)pp.203-208.

Language：English   Publishing type：Research paper (scientific journal)  

Mechanism of Isothermal Eutectoid Transformation in High Carbon Stainless Steels
T. TSUCHIYAMA Y. ONO and S. TAKAKI
ISIJ International
Vol.37 7(1997)pp.715-720.

DOI： 10.2355/isijinternational.37.715

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Partial Solution Treatment on Martensitic Transformation of 12%Cr Steels
T. TSUCHIYAMA and S. TAKAKI
Tetsu-to-Hagane
Vol.82 12(1996)pp.1035-1040.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Austenite Grain Size Control by Insoluble Carbide in Martensitic Stainless Steels
T. TSUCHIYAMA S. TAKAKI and S. NAKAMURA
Tetsu-to-Hagane
Vol.81 2(1995)pp.147-152.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effects of Insoluble Carbide on Microstructure and Hardness of Matensitic Stainless Steels
T. TSUCHIYAMA S. TAKAKI and S. NAKAMURA
Tetsu-to-Hagane
Vol.80 12(1994)pp.938-943.

Event date： 2025.3

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Venue：九州大学筑紫キャンパス   Country：Japan  

Event date： 2024.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学筑紫キャンパス   Country：Japan  

Event date： 2024.6

Language：Japanese   Presentation type：Poster presentation  

Venue：九州大学筑紫キャンパス   Country：Japan  

Event date： 2024.6

Language：Japanese   Presentation type：Poster presentation  

Venue：九州大学筑紫キャンパス   Country：Japan  

Event date： 2024.6

Language：Japanese   Presentation type：Poster presentation  

Venue：九州大学筑紫キャンパス   Country：Japan  

Event date： 2024.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京工業大学   Country：Japan  

Event date： 2024.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京工業大学   Country：Japan  

Event date： 2024.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京工業大学   Country：Japan  

Event date： 2024.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京理科大学葛飾キャンパス   Country：Japan  

Event date： 2024.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京理科大学葛飾キャンパス   Country：Japan  

Event date： 2024.3

Language：Japanese  

Venue：東京理科大学葛飾キャンパス   Country：Japan  

Event date： 2024.3

Language：Japanese  

Venue：東京理科大学葛飾キャンパス   Country：Japan  

Event date： 2024.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京理科大学葛飾キャンパス   Country：Japan  

Event date： 2024.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京理科大学葛飾キャンパス   Country：Japan  

Event date： 2023.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学筑紫キャンパス   Country：Japan  

Event date： 2023.11

Language：English  

Venue：済州国際コンベンションセンター   Country：Korea, Republic of  

Event date： 2023.11

Language：English  

Venue：パシフィコ横浜   Country：Japan  

Event date： 2023.11

Language：English  

Venue：パシフィコ横浜   Country：Japan  

Event date： 2023.11

Language：English   Presentation type：Oral presentation (general)  

Venue：パシフィコ横浜   Country：Japan  

Event date： 2023.11

Language：English  

Venue：パシフィコ横浜   Country：Japan  

Event date： 2023.11

Language：English   Presentation type：Oral presentation (general)  

Venue：パシフィコ横浜   Country：Japan  

Event date： 2023.7

Language：English  

Venue：TU-Wien   Country：Austria  

Event date： 2023.7

Language：English  

Venue：TU-Wien   Country：Austria  

Event date： 2023.7

Language：English   Presentation type：Oral presentation (general)  

Venue：TU-Wien   Country：Austria  

Event date： 2023.7

Language：English   Presentation type：Oral presentation (general)  

Venue：TU-Wien   Country：Austria  

Event date： 2023.7

Language：English   Presentation type：Oral presentation (general)  

Venue：TU-Wien   Country：Austria  

Event date： 2023.7

Language：English   Presentation type：Oral presentation (general)  

Venue：TU-Wien   Country：Austria  

Event date： 2023.7

Language：English   Presentation type：Oral presentation (general)  

Venue：TU-Wien   Country：Austria  

Event date： 2023.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：くまもと県民交流館パレア   Country：Japan  

Event date： 2023.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：くまもと県民交流館パレア   Country：Japan  

Event date： 2023.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：くまもと県民交流館パレア   Country：Japan  

Event date： 2023.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：くまもと県民交流館パレア   Country：Japan  

Event date： 2023.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：くまもと県民交流館パレア   Country：Japan  

Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京工業大学   Country：Japan  

Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京工業大学   Country：Japan  

Event date： 2023.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京大学   Country：Japan  

Event date： 2023.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京大学   Country：Japan  

Event date： 2023.3

Language：Japanese  

Venue：東京大学   Country：Japan  

Event date： 2023.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京大学   Country：Japan  

Event date： 2023.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京大学   Country：Japan  

Event date： 2023.3

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：東京大学   Country：Japan  

Event date： 2023.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京大学   Country：Japan