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Effect of cr and isothermal holding temperature on microstructure and properties of complex phase steel with high formability(CH steel)

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Journal of Iron and Steel Research International 2023年第2期30卷 328-337页

作者： Xiao-hong Chu Peng-fei Gao Wei-jian Chen Feng Li Tao Kang Yan Zhao Xian-dong Yin Zheng-zhi Zhao Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing100083China Beijing Laboratory for Modern Transportation Advanced Metal Materials and Processing Technology University of Science and Technology BeijingBeijing100083China Technical Center Shougang Jingtang United Iron and Steel Co.Ltd.Tangshan063200HebeiChina

The effects of cr contents(0.3 and 1.0 wt.%)and isothermal holding temperatures(400,440,and 480℃)on the microstructure evolution and properties of complex phase steel with high formability(CH steel)were investigated using dilatometry,scanning electron microscopy,transmission electron microscopy(TEM),and X-ray *** results show that the microstructures of CH steel with 0.3 wt.%cr are ferrite,granular bainite,martensite,and retained austenite,while no ferrite is observed in the microstructure of CH steel with 1.0 wt.%cr in the same *** promotes the precipitation of(Nb,Ti)C in the high-temperature austenite region through theoretical calculations and TEM *** retards the bainite transformation and refines the grain size of CH ***,as isothermal holding temperature increases from 400 to 480℃,the bainite and retained austenite fractions of two CH steels decrease,while the martensite fraction increases in the steels after final ***,the strength has an increasing tendency and the total elongation has a decreasing tendency with increasing isothermal temperature.

关键词： Complex phase steel High formability steel CH steel cr Isothermal holding temperature Microstructure Mechanical property

Interaction of Mechanical and Electrochemical Factors duringCorrosion Fatigue of Fe-26cr-1Mo Stainless Steel in 1M H_2SO_4 Solution

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Journal of Materials Science & Technology 1995年第3期11卷 181-186页

作者： Jianqiu WANG Jin LI Ziyong ZHU and Wei KE (Corrosion Science Laboratory, Institute of Corrosion and Protection of Metals Chinese Academy of Sciences, Shenyang, 110015, China)Qishan ZANG and Zhongguang WANG (State Key Laboratory for Fatigue and Fracture Inst of Corrosion and Protection of Metals Chinese Acad of Sciences Shenyang China

The cyclic plastic straining electrode technique has been used to investigate the transient electrochemical behaviour of Fe-26cr1Mo stainless steel in 1M H2SO4 solution at a passive *** influence of plastic strain amplitude and plastic strain rate on the dissolution current response was analysed. The experimental results showed that the transient current was dependent on the competitive process of the surface film rupture and repassivation of the new surface. The high plastic strain amplitude and the high plastic strain rate caused a change of electrochemical activity of specimen surface. In the condition of low strain amplitude and strain rate, the characteristics of current response was mainly relative tp the process of new surface *** competition kinetics has been analysed through the comparison of plastic strain rate and repassivating rate

关键词： Mo cr Interaction of Mechanical and Electrochemical Factors duringCorrosion Fatigue of Fe-26cr-1Mo Stainless Steel in 1M H2SO4 Solution Fe SO

Layer-structured cr/cr_(x)N coating via electroplating-based nitridation achieving high deuterium resistance as the hydrogen permeation barrier

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Journal of Advanced Ceramics 2022年第12期11卷 1944-1955页

作者： Liyu ZHENG Heping LI Jun ZHOU Xinluo TIAN Zhongyang ZHENG Long WANG Xinyun WANG Youwei YAN State Key Laboratory of Materials Processing and Die&Mould Technology International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma PhysicsSchool of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China Southwestern Institute of Physics Chengdu 610225China

Hydrogen isotope permeation through structural materials is a key issue for developing nuclear fusion energy,which will cause fuel loss and radioactive *** ceramic coatings with high thermal shock and hydrogen resistance is an effective strategy to solve this *** this work,a layer-structured cr/cr_(x)N coating was successfully fabricated by a facile electroplatingbased nitridation technique,which is easy,facile,and applicable to coating complex-shaped *** cr/cr_(x)N coating,composed of a bottom Fe/cr interdiffusion zone,a middle cr layer,and a top cr_(x)N layer,exhibits high bonding strength,high anti-thermal-shock ability,and high deuterium permeation *** bonding strength achieves 43.6 *** cr/cr_(x)N coating remains intact even after suffering 300 thermal shock cycles under a 600℃–water *** optimizing the nitridation temperature,the cr/cr_(x)N coating achieves a deuterium permeation reduction factor(PRF)as high as 3599 at 500℃.Considering its scalable fabrication technique and considerable properties,the developed cr/cr_(x)N coating may serve as a novel high-performance hydrogen permeation barrier in various fields.

关键词： hydrogen permeation cr_(x)N cr electrodeposition thermal shock resistance

Effect of cr Doping on the Surface Characteristics of Ni Metal Studied with First-Principles Calculation

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Acta Metallurgica Sinica(English Letters) 2019年第4期32卷 461-470页

作者： Xian-Feng Sun Hai-Tao Wang En-Hou Han CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of Sciences School of Materials Science and Engineering University of Science and Technology of China

The influence of cr doping on the surface characteristics of Ni metal, including the surface energy, work function,adsorption and dissociation, has been investigated by means of first-principles calculation based on density functional theory. The results reveal that with the increase in cr doping amount, the surface energies for all(111),(110) and(100)surfaces increase, whereas the work functions of(111) and(100) surfaces decrease followed by an increase and that of(110) surface has been decreasing. On the typical Ni(111) and Ni-cr(111) surfaces, the adsorption energies follow the sequence O > OH > H > H_2O, and the doping of cr increases the chemical activity of surfaces leading to the improvement of adsorption energies. The H_2O dissociating to OH and H is easier than the subsequent OH dissociating to O and H. The addition of cr into Ni surface decreases the energy barriers and significantly increases the reaction rate constants.

关键词： Density functional theory Surface characteristics Nickel cr addition Atomistic simulation

Enhanced wetting and properties of carbon/carbon-Cu composites with cr_3C_2 coatings by cr-solution immersion method

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Journal of Materials Science & Technology 2018年第3期34卷 458-465页

作者： Bo Kong Jinming Ru Hongdi Zhang Tongxiang Fan State Key Laboratory for Metal Matrix Composite Shanghai Jiaotong University Institute of Advanced Manufacturing and Modern Equipment Technology Jiangsu University

A facile ammonium-dichromate solution immersion method was introduced to synthesize the copperwettable cr3C2 coating on and inside the carbon-carbon （C/C） preform. The formation mechanism and the microstructures of the cr3C2 coatings were studied. The contact angle between molten copper and the C/C decreased from 140°to 60°, demonstrating the significant improvement in the wettability. The cr3C2- coated C/C-Cu composite with only 4.2% porosity and 3.69 gcm^-3 density was manufactured through copper infiltration. As a result, the thermal and electrical conductivity of the modified C/C-Cu increased significantly due to the infiltrated copper. Also the mechanical properties of the composites including both the flexural and compressive strengths were enhanced by over 100%. The modified C/C-Cu composite exhibited lower friction coefficients and wear rates for different load levels than those of the commercial C/Cu composite. These results demonstrate the potential of the modified C/C-Cu material for use in electrical contacts.

关键词： Enhanced wetting and properties of carbon/carbon-Cu composites with cr3C2 coatings by cr-solution immersion method cr Cu

cr2+:ZnS Saturable Absorber Passively Q-Switched Ho:LuVO4 Laser

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Chinese Physics Letters 2015年第10期32卷 59-62页

作者：崔铮姚宝权段小明白爽李江袁晋鹤戴通宇李超宇潘裕柏 National Key Laboratory of Tunable Laser Technology Harbin Institute of Technology Harbin 150001 Key Laboratory of Transparent and Opto-functional Advanced Inorganic Materials Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 200050

We report a cw Tm：YAP laser resonantly pumped Ho：LuV04 laser in passively Q-switched （PQS） mode with cr2＋：ZnS as a saturable absorber （SA）. The influence of different transmittances of the output coupler on laser output performance is analyzed. With T = 50%, the max/mum PQS average output power of 2.3 W is ob- tained, corresponding to the slope efficiency and the optical-optical conversion efficiency are 35.1% and 19.8%, respectively. Also, the minimum pulse width of 100ns is achieved at the maximum pulse repetition frequency of 34.2kHz. When the maximum cw output power is 2.7W, the beam quality factor of the horizontal direc- tion Mx2 = 1.04 and the vertical direction M2 = 1.10 are obtained. In addition, the central wavelength of the laser output remains to be 2057.5nm with the output coupler transmittances of 50% and 60% in both cw and PQS operations. The results show that the cr2＋：ZnS can be used as an SA in a Ho：LuVO4 laser around 2-μm wavelength.

关键词： Ho ZnS Saturable Absorber Passively Q-Switched Ho:LuVO4 Laser cr

Single cr atom catalytic growth of graphene

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Nano Research 2018年第5期11卷 2405-2411页

作者： Huy Q. Ta Uang Zhao Wanjian Yin Darius Pohl Bemd Rellinghaus Thomas Gemming Barbara Trzebicka Justinas Palisaitis Gao Jing Per O. A. Persson Zhongfan Liu Alicja Bachmatiuk Mark H. Rummeli Soochow Institute for Energy and Materials Innovations College of Physics Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology Soochow University Suzhou 215005 China Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province Soochow University Suzhou 215006 China Centre of Polymer and Carbon Materials Polish Academy of Sciences M. Curie-Sklodowskiej 34 Zabrze 41-819 Poland IFW Dresden Helmholtz Strasse 20 01069 Dresden Germany Department of Physics Chemistry and Biology (IFM) Linkoping University SE-581 83 Linkoping Sweden Center for Nanochemistry Beijing Science and Engineering Centre for Nanocarbons Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

Single atoms are the ultimate minimum size limit for catalysts. Graphene, as an exciting, ultimately thin （one atom thick） material can be imaged in a transmission electron microscope with relatively few imaging artefacts. Here, we directly observe the behavior of single cr atoms in graphene mono- and di-vacancies and, more importantly, at graphene edges. Similar studies at graphene edges with other elemental atoms, with the exception of Fe, show catalytic etching of graphene. Fe atoms have been shown to both etch and grow graphene. In contrast, cr atoms are only observed to induce graphene growth. Complementary theoretical calculations illuminate the differences between Fe and cr, and confirm single cr atoms as superior catalysts for sp^2 carbon growth.

关键词： in situ transmission electron microscope (TEM) electron driven catalysis cr single atom graphene synthesis

Effects of cr content on corrosion behaviour and corrosion products of spring steels

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Journal of Iron and Steel Research International 2019年第9期26卷 1000-1010页

作者： Mao-fang Zuo Yin-li Chen Zhen-li Mi Yi-de Wang Hai-tao Jiang Institute of Engineering Technology University of Science and Technology BeijingBeijing 100083China Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China

Neutral salt spray corrosion experiments of spring steels with different cr contents were carried out for different corrosion periods. The optical microscope was used to observe the macroscopic corrosion morphology of the steel surface. The corrosion pit morphology of steel surface was observed by laser scanning confocal microscopy and scanning electron microscopy, and three-dimensional simulation was carried out. At the same time, the corrosion products (rust layer) were qualitatively and quantitatively analysed by X-ray diffraction. As the results show, cr is beneficial to improving corrosion resistance of the experimental steel matrix, and the higher the content of cr, the stronger the corrosion resistance will be. With increase in cr content in steel, the development of corrosion process will be more effectively suppressed. With the increase in cr content, the denser the corrosion products, the stronger the bond with the metal matrix is. The corrosion products have obvious stratification;the outer layer is mainly composed of c-FeOOH, which is relatively loose and not firmly integrated with the matrix, while the inner layer contains a-FeOOH and Fe3O4, which are relatively dense and closely integrated with the matrix. The types of corrosion are constantly changing during different phases of corrosion.

关键词： Spring steel cr content Corrosion behaviour Corrosion product Rust layer

Characteristics of the stabilized/solidified municipal solid wastes incineration fly ash and the leaching behavior of cr and Pb

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Frontiers of Environmental Science & Engineering 2016年第1期10卷 192-200页

作者： Yan SHAO Haobo HOU Guangxing WANG Sha WAN Min ZHOU School of Resource and Environment Science Wuhan University Wuhan 430072 China GNSS Research Center Wuhan University Wuhan 430072 China

Fly ash is a hazardous byproduct of municipal solid wastes incineration （MSWI）. An alkali activated blast fumace slag-based cementifious material was used to stabilize/solidify the fly ash at experimental level. The characteristics of the stabilized/solidified fly ash, including metal leachability, mineralogical characteristics and the distributions of metals in matrices, were tested by toxic characteristic leaching procedure （TCLP）, X-ray diffrac- tion （XRD） and scanning electron microscopy-energy dispersive spectrometer （SEM-EDS） respectively. Contin- uous acid extraction was utilized to extract metal ions and characterize their leaching behavior. The stabilization/ solidification procedure for MSWI fly ash demonstrates a strong fixing capacity for the metals by the formation of C- S-H phase, hydrated calcium aluminosilicate and ettringite. The stabilized/solidified fly ash shows a dense and homogeneous microstructure. cr is mainly solidified in hydrated calcium aluminosilicate, C-S-H and ettringite phase through physical encapsulation, precipitation, adsorption or substitution mechanisms, and Pb is mainly solidified in C-S-H phase and absorbed in the Si-O structure.

关键词： municipal solid waste incineration (MSWI)fly ash blast furnace slag leaching behavior cr Pb