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Effect of vanadium and chromium on the microstructural features of V–Cr–Mn–Ni spheroidal carbide cast irons

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International Journal of Minerals,Metallurgy and Materials 2014年第11期21卷 1096-1108页

作者： V.G.Efremenko k.shimizu A.P.Cheiliakh T.V.kozarevskaya k.kusumoto k.Yamamoto Department of Metal Science and Heat Treatment of Metals Pryazovskyi State Technical UniversityMariupol 87500 Ukraine Manufacturing and Engineering Design Center Muroran Institute of TechnologyMuroran 050-8585 Japan

The objective of this investigation is to study the influence of vanadium（5.0wt%–10.0wt%） and chromium（0–9.0wt%） on the microstructure and hardness of Cr-V-Mn-Ni white cast irons with spheroidal vanadium carbides. The alloys＇ microstructural features are presented and discussed with regard to the distribution of phase elements. The structural constituents of the alloys are spheroidal VC, proeutectoid cementite, ledeburite eutectic, rosette-shaped carbide eutectic（based on M7C3）, pearlite, martensite, and austenite. Their combinations and area fraction（AF） ratios are reported to be influenced by the alloys＇ chemical composition. Spheroidized VC particles are found to be sites for the nucleation of carbide eutectics. Cr and V are shown to substitute each other in the VC and M7C3 carbides, respectively. Chromium alloying leads to the formation of a eutectic（γ-Fe ＋ М7С3）, preventing the appearance of proeutectoid cementite in the structure. Vanadium and chromium are revealed to increase the total carbide fraction and the amount of austenite in the matrix. Cr is observed to play a key role in controlling the metallic matrix microstructure.

关键词： cast irons carbides microstructure vanadium chromium austenite pearlite

New developments in high-pressure X-ray diffraction beamline for diamond anvil cell at SPring-8

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Matter and Radiation at Extremes 2020年第1期5卷 49-58页

作者： N.Hirao S.I.kawaguchi k.Hirose k.shimizu E.Ohtani Y.Ohishi Japan Synchrotron Radiation Research Institute SayoHyogo 679-5198Japan Department of Earth and Planetary Science The University of TokyoTokyo 113-0033Japan Earth-Life Science Institute Tokyo Institute of TechnologyTokyo 152-8550Japan Center of Science and Technology Under Extremes Conditions Graduate School of Engineering ScienceOsaka UniversityOsaka 560-8531Japan Department of Earth Science Graduate School of ScienceTohoku UniversitySendai 980-8578Japan

An overview of the recently renovated high-pressure X-ray diffraction(XRD)BL10XU beamline for the diamond anvil cell at SPring-8 is presented.The renovation includes the replacement of the X-ray source and monochromator,enhanced focusing systems for high-energy XRD,and recent progress in the sample environment control techniques that are available for high-pressure studies.Other simultaneous measurement techniques for combination with XRD,such as Raman scattering spectroscopy and Mossbauer spectroscopy,have been developed to obtain complementary information under extreme conditions.These advanced techniques are expected to make significant contributions to in-depth understanding of various and complicated high-pressure phenomena.The experience gained with the BL10XU beamline could help promote high-pressure research in future synchrotron radiation facilities.

关键词： beam gained extreme

Abrasive resistance of metastable V–Cr–Mn–Ni spheroidal carbide cast irons using the factorial design method

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International Journal of Minerals,Metallurgy and Materials 2016年第6期23卷 645-657页

作者： V.G.Efremenko k.shimizu A.P.Cheiliakh T.V.Pastukhova Yu.G.Chabak k.kusumoto Department of Metal Science and Heat Treatments of Metals Pryazovskyi State Technical University Department of Mechanical Aerospace and Materials Engineering Muroran Institute of Technology

Full factorial design was used to evaluate the two-body abrasive resistance of 3wt%C–4wt%Mn–1.5wt%Ni spheroidal carbide cast irons with varying vanadium（5.0wt%–10.0wt%） and chromium（up to 9.0wt%） contents. The alloys were quenched at 920℃. The regression equation of wear rate as a function of V and Cr contents was proposed. This regression equation shows that the wear rate decreases with increasing V content because of the growth of spheroidal VC carbide amount. Cr influences the overall response in a complex manner both by reducing the wear rate owing to eutectic carbides（M7C3） and by increasing the wear rate though stabilizing austenite to deformation-induced martensite transformation. This transformation is recognized as an important factor in increasing the abrasive response of the alloys. By analyzing the regression equation, the optimal content ranges are found to be 7.5wt%–10.0wt% for V and 2.5wt%–4.5wt% for Cr, which corresponds to the alloys containing 9vol%–15vol% spheroidal VC carbides, 8vol%–16vol% M7C3, and a metastable austenite/martensite matrix. The wear resistance is 1.9–2.3 times that of the traditional 12wt% V–13wt% Mn spheroidal carbide cast iron.

关键词： cast irons carbides abrasive resistance factorial design

Theoretical study of coexistence of ordering and spinodal decomposition

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Science China(Technological Sciences) 1996年第4期39卷 412-423页

作者：任晓兵王笑天 T.Tadaki k.shimizu National Laboratory of Solid State Microstructures Nanjing UniversityNanjing 210093China College of Materials Science and Engineering Xi'an Jiaotong UniversityXi'an 710049. China Institute for Scientific and Industrial Research Osaka UniversityOsaka 567Japan Department of Mechanical Engineering Kanazawa Institute of TechnologyIshikawa 921Japan

According to the conventional theory of solid solutions (the nearest neighbor atomic interaction model),ordering and spinodal decomposition/clustering are mutually exclusive processes.However,it has been found that the coexistence of ordering and spinodal decomposition (COSD) occurs in a large number of alloys.This fact gave a strong challenge to the conventional theory.A statistical investigation revealed that the COSD was closely related to large atomic-siae factors.It was thus proposed that the COSD stemmed from the long-range elastic interactions due to atomic-si?E disparity.In order to verify this idea,the formulism of concentration waves was applied to calculating the elastic interactions.The results proved that long-range atomic elastic interactions promoted both ordering and spinodal decomposition.A possible application of the COSD reaction was proposed,i.***.using this reaction to fabricate high-performance "natural nano-alloys".

关键词： ordering and spinodal decomposition elastic interactions atomic-size factor phase transformation nano-materials.

Modelling of Edge Plasma on JT-60U Tokamak by Using SOLPS5.0 Code

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Plasma Science and Technology 2011年第3期13卷 302-306页

作者：陈一平 H. kAWASHIMA N. ASAkURA k. shimizu H. TAkENAGA Institute of Plasma Physics Chinese Academy of Sciences Hefei 230031 China Japan Atomic Energy Agency Naka-shi Ibaraki-Ken 311-0193 Japan

The edge transport code SOLPS5.0 is used to model edge plasmas in the experi- mental shots on JT-60U and the profiles of the transverse particle and heat transport coefficients D, Xe and Xi along the outer midplane are obtained by fitting the simulational results to the experimental data in L-mode shot 39090 and H-mode shots 37851, 37856. The modelling and fitting results show that within the pedestal region in H-mode shots 37851 and 37856 the radial particle transport coefficient D exhibits a significant drop, but, for L-mode shot 39090, the obvious drop in both D and Xe was not found.

关键词： SOLPS5.0 JT-60U modelling

CRYSTAL　STRUCTURE　OF　A　LONG－PERIOD　ORDERED　PHASE　IN　Fe－C　MARTENSITE　AND　COMPUTER　SIMULATION　OF　ITS　ELECTRON　DIFFRACTION　PATTERNS

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Acta Metallurgica Sinica(English Letters) 1996年第1期9卷 23-26页

作者： REN Xiaobing WANG Xiaotian k.shimizu T.TADAkI(National Laboratory of Solid State Microstructures,Nanjing University Nanjing 210093,China)(School of Materials Science and Engineering,Xi’an Jiaotong University Xi’an 710049,China)(kanazawa Institute of Techn Nanjing Univ Nanjing China

Different structure models of a long-period ordered phase in Fe-C martenstie formed during aging have been checked by computer simulation of electron diffraction(ED) patterns based on these models.The results showed that the simulated ED pattern of γ'-FexC(Ⅱ) model proposed by the present authors is in good agreement with experimentally observed ED pattern.It was also confirmed that the incommensurate superperiod stems from the coexistence of several γ'-Fe_xC(H) phases with different superperiods.The Fe(144)C(24)(Fe6C) model proposed by Uwakweh et al.generated ED patterns remarkably different from the experimental ones.

关键词： Fe-C martensite,long-period ordered phase,crystal structure,computer simulation,electron diffraction pattern

Surface modification of stratum corneum for drug delivery and skin care by microplasma discharge treatment

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Plasma Science and Technology 2019年第6期21卷 1-8页

作者： J kRISTOF T AOSHIMA M BLAJAN k shimizu Graduate School of Science and Technology Shizuoka University 432-8561 Hamamatsu Japan Department of Electrical and Electronic Engineering Shizuoka University 432-8561 Hamamatsu Japan Organization for Innovation and Social Collaboration Shizuoka University 432-8561 Hamamatsu Japan

Human skin is the largest organ and also the main barrier that prevents foreign substances from entering the body.The surface properties of the skin are relevant for transdermal drug delivery and cosmetics.Yucatan micropig skin is used as a substitute for human skin.A microplasma electrode is used for surface modification of the skin epidermal layer of the Yucatan micropig.Microplasma dielectric barrier discharge has a thin dielectric as a barrier (~50 μm) and a frequency of 25 kHz.The surface properties of the epidermal layer were characterized by the measurement of the contact angle of the water droplet.The effects of different gases such as air,nitrogen,oxygen,helium or argon were compared.The change of the contact angle is temporal and it is returned to its initial state after several hours.Among the gases used for plasma ignition,oxygen and argon were the most effective for skin treatment.The distance of the skin from the electrode and the treatment time played a crucial roles in the increasing water contact angle.Changes of surface atomic concentration were determined by x-ray photoelectron spectroscopy.After microplasma treatment,the oxygen and nitrogen concentration increased at the skin surface.

关键词： microplasma contact angle skin stratum corneum XPS

Effect of Elastic Energy due to Atomic Size Factor on Ordering and Decomposition Behaviour of Binary Solid Solutions

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Journal of Materials Science & Technology 1996年第2期12卷 135-142页

作者： Ren, XB Wang, XT shimizu, k Tadaki, T XIAN JIAOTONG UNIV COLL MAT SCI & ENGNXIAN 710049PEOPLES R CHINA OSAkA UNIV INST SCI & IND RESIBARAKIOSAKA 567JAPAN

A theory recently developed by the present authors is applied to the study of the effect of elastic energy due to atomic size factor on the transformation behaviour of binary solid solutions. It is found that elastic interaction energy (EIE), which is a part of the total elastic energy, plays a key role in both ordering elastic interaction ordering (EIO) and spinodal decomposition. The present study gives a reasonable explanation to the historical dilemmas, ''elastic energy paradox'' and ''atomic size factor paradox''. By solving these confusing problems, the coexistence of ordering (EIO) and decomposition, which has been regarded as impossible by conventional theories, can be well understood. The mechanism is as follows: lowering of elastic energy demands EIO, and such an ordering provides a driving force for spinodal decomposition. Therefore, in alloys with large atomic size factor, spinodal decomposition is preceded and induced by ordering. Ordering and spinodal decomposition are thus closely related processes to each other.

关键词： Solid solutions

Elastic Energy and Elastic Interaction Ordering of Binary Solid Solutions

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Journal of Materials Science & Technology 1996年第1期12卷 57-68页

作者： Ren, XB Wang, XT shimizu, k Tadaki, T XIAN JIAOTONG UNIV COLL MAT SCI & ENGN XIAN 710049 PEOPLES R CHINA OSAkA UNIV INST SCI & IND RES IBARAKI OSAKA 567 JAPAN

A theory in the framework of continuum elasticity has been developed to calculate the total contribution of ''atomic size effect'' or ''strain energy effect'' to free energy of binary solid solutions. It is found that elastic free energy consists of two parts: elastic self energy (ESE), and elastic interaction energy(EIE). The former is a function of composition alone, the latter is also a function of atomic configuration. Minimization of total elastic free energy with respect to atomic arrangement results in an ordered arrangement of atoms, which is called elastic interaction ordering (EIO), as it originates from elastic interaction among atoms. EIO is a kind of local ordering within a ''characteristic range'', and it is found to be important in determining the state of solid solutions and structures of superlattices. The present theory also gives good explanation to the coexistence of ordering and decomposition which can not be understood in conventional theories.

关键词： Solid solutions