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Effect of Mn Content on Microstructure and Cryogenic Mechanical Properties of a 7%Ni Steel

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Acta Metallurgica Sinica(English Letters) 2018年第7期31卷 699-705页

作者： hong-Wei Cao Xing-hong Luo guo-Feng zhan Shi Liu School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China CAS Key Laboratory of Nuclear Materials and SafetyAssessment Institute of Metal ResearchChinese Academyof SciencesShenyang 110016China Research and Development Center of Wuhan Iron and Steel(Group)Corp Wuhan 430080China

The effect of Mn content on the microstructure and cryogenic mechanical properties of a 7% Ni steel was investigated within the Mn content range from 0.13% to 0.36%. The microstructure of the steel as determined by optical microscopy, scanning electron microscopy, transmission electron microscopy, electron backscattering diffraction and X-ray diffraction was presented, and the low-temperature mechanical properties were given. The size of prior austenite grain did not change a lot as Mn content increased. Film-like reversed austenite, having high stability, was found mainly in the specimens with lower Mn content; however, in the specimen with the highest Mn content, the role of Mn was not obvious in stabilizing reversed austenite. Besides, with increasing Mn content, the amount of reversed austenite at grain boundaries gradually decreased. The variable Mn content had a significant effect on cryogenic toughness~ but not apparent on cryogenic tensile strength or yield strength. An excellent combination of cryogenic tensile and impact properties was obtained when Mn content of steel was 0.13%.

关键词： 7% Ni steel Mn content Microstructure Reversed austenite Cryogenic mechanical properties

MFSR: Maximum Feature Score Region-based Captions Locating in News Video Images

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International Journal of Automation and computing 2018年第4期15卷 454-461页

作者： Zhi-Heng Wang Chao guo hong-Min Liu zhan-Qiang Huo School of Computer Science and Technology Henan Polytechnic University

For news video images, caption recognizing is a useful and important step for content understanding. Caption locating is usually the first step of caption recognizing and this paper proposes a simple but effective caption locating algorithm called maximum feature score region （MFSR） based method, which mainly consists of two stages： In the first stage, up/down boundaries are attained by turning to edge map projection. Then, maximum feature score region is defined and left/right boundaries are achieved by utilizing MFSR. Experiments show that the proposed MFSR based method has superior and robust performance on news video images of different types.

关键词： News video images captions recognizing captions locating content understanding maximum feature score region（MFSR）.

Removal of phosphorus-rich phase from high-phosphorous iron ore by melt separation at 1573 K in a super-gravity field

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International Journal of Minerals,Metallurgy and Materials 2016年第7期23卷 743-750页

作者： Jin-tao Gao Lei guo Yi-wei Zhong hong-ru Ren zhan-cheng guo State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing

A new approach of removing the phosphorus-rich phase from high-phosphorous iron ore by melt separation at 1573 K in a super-gravity field was investigated. The iron？slag separation by super-gravity resulted in phosphorus being effectively removed from the iron-rich phase and concentrated as a phosphorus-rich phase at a temperature below the melting point of iron. The samples obtained by super-gravity exhibited obvious layered structures. All the iron grains concentrated at the bottom of the sample along the super-gravity direction, whereas the molten slag concentrated in the upper part of the sample along the opposite direction. Meanwhile, fine apatite crystals collided and grew into larger crystals and concentrated at the slag–iron interface. Consequently, in the case of centrifugation with a gravity coefficient of G = 900, the mass fractions of the slag phase and iron-rich phase were similar to their respective theoretical values. The mass fraction of MFe in the iron-rich phase was as high as 97.77wt% and that of P was decreased to 0.092wt%.

关键词： ironmaking super-gravity melt separation dephosphoration

Recent progress in hair follicle stem cell markers and their regulatory roles

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World Journal of Stem Cells 2024年第2期16卷 126-136页

作者： Yi-zhan Xing Hai-Ying guo Fei Xiang Yu-hong Li Department of Cell Biology Army Medical UniversityChongqing 400038China Institute of Burn Research Southwest HospitalArmy Medical UniversityChongqing 400038China

Hair follicle stem cells(HFSCs)in the bulge are a multipotent adult stem cell population.They can periodically give rise to new HFs and even regenerate the epidermis and sebaceous glands during wound healing.An increasing number of biomarkers have been used to isolate,label,and trace HFSCs in recent years.Considering more detailed data from single-cell transcriptomics technology,we mainly focus on the important HFSC molecular markers and their regulatory roles in this review.

关键词： Hair follicle stem cells Bulge Secondary hair germ Marker Single-cell RNA-sequencing

Influence of Ca treatment on particle-microstructure relationship in heat-affected zone of shipbuilding steel with Zr-Ti deoxidation after high-heat-input welding

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Journal of Iron and Steel Research(International) 2022年第8期29卷 1291-1298页

作者： hong-bo Liu Ju Kang Xiu-juan Zhao Cai-dong zhang zhang-guo Lin hong-yong Yao Zhi-qiang Tian zhan-li Liu Jie Li Chao Li Technology Research Institute HBIS GroupShijiazhuang 050023HebeiChina Beijing Key Laboratory of Pipeline Critical Technology and Equipment for Deepwater Oil and Gas Development Beijing Institute of Petrochemical TechnologyBeijing 102617China Department of Material Engineering Hebei Vocational University of Industry and TechnologyShijiazhuang 050091HebeiChina HBIS Company Limited Shijiazhuang 050023HebeiChina School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China HBIS Group Shisteel Company Shijiazhuang 050031HebeiChina

The effects of Ca treatment on the particle, microstructure, and toughness of heat-affected zone (HAZ) of shipbuilding steel with Zr-Ti deoxidation after high-heat-input welding were investigated. The simulated welding at a high-heat-input welding of 200 kJ/cm was carried out using Gleeble-3800 welding simulation. Then, particle characteristics were characterized using an Aztec-Feature automatic particle analysis system. Additionally, an in-situ observation experiment was performed to study the relationships between particle and microstructure by high-temperature confocal laser scanning microscopy (HT-CLSM). The results indicated that the average HAZ toughness at -40 ℃ was increased from 183 to 290 J by adding 0.0026 wt.% Ca. Meanwhile, the formation of acicular ferrite ratio was increased from 49.34% to 60.28% due to the addition of Ca. The scanning electron microscopy results clearly showed that CaO-Al_(2)O_(3)-TiOx-ZrO_(2)-MnS particles could act as effective nucleation sites for the formation of acicular ferrite, which has been verified by the observation of the particle-microstructure relationship under HT-CLSM. Furthermore, particle characterization results show that the cumulative frequency of particles with the size of 1-3 lm was 33.2% in HAZ of Zr-Ti shipbuilding steel but 66.2% in HAZ of Zr-Ti-Ca shipbuilding steel.

关键词： Shipbuilding steel Heat-affected zone Impact toughness Microstructure Particle characterization

Highly Regioselective Sequential 1,1-Dihydrosilylation of Terminal Aliphatic Alkynes with Primary Silanes

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Chinese Journal of Chemistry 2019年第5期37卷 457-461页

作者： Zhaoyang Cheng Shipei Xing Jun guo Biao Cheng Lan-Fang Hu Xing-hong zhang zhan Lu Deportment of Chemistry Zhejiang University Hangzhou Zhejiang 310058 China MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang University Hangzhou Zhejiang 310027 China

Summary of main observation and conclusion A regioselective double 1,1-hydrosilylation of terminal aliphatic alkynes with primary silanes catalyzed by one cobalt catalyst has been developed. gem-Bis(dihydrosilyl)alkanes containing four silicon-hydrogen bonds are efficiently constructed in an atom-economical man ner. Tolerated substrates include simplest alkyne-ethyne, a complicated drug derivative and various functi on alized terminal aliphatic alkynes. Asymmetric approach using two catalysts is achieved with excelle nt enan tioselectivities to access corresp on ding chiral products. The tra nsformations of Si—H bonds into Si—C, Si—O, and Si —F bonds and the synthesis of enantioriched a-hydroxysilane show synthetic utility.

关键词： cobalt derivative utility

Upgrade of nickel and iron from low-grade nickel laterite by improving direct reduction-magnetic separation process

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Journal of Iron and Steel Research(International) 2022年第8期29卷 1164-1175页

作者： hong-yu Tian Zheng-qi guo Ruo-ning zhan Jian Pan De-qing Zhu Cong-cong Yang Liao-ting Pan Xue-zhong Huang School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083HunanChina Beibu Gulf New Materials Co. Ltd.Beihai 536000GuangxiChina

Low-grade saprolite nickel laterite,characterized by complicated minerals composition and fine-grained and complex dissemination,was commonly treated with a low recovery efficiency of Ni and Fe by conventional methods.Hence,an improved direct reduction and magnetic separation process was proposed.Meanwhile,the mechanisms on the enhanced growth of the Ni-Fe particles and the phase transformation in the nickel laterite pellets were explored.The low-nickel concentrates as a nucleating agent can obviously decrease the activation energy for growth of Ni-Fe alloy particles during the improved direct reduction process from 197.10 to 154.81 kJ/mol when the low-nickel concentrates were added from 0 to 20%.Hence,it is able to decrease nucleation barrier,induce the growth of Fe-Ni alloy particles and increase their average size.As a result,the size of Ni-Fe particles in the pellets from less than 10 lm grew to more than 20 lm,which is beneficial for the full liberation and recovery of Ni and Fe in subsequent magnetic separation process.Therefore,the preferable Ni-Fe alloy concentrates with 6.44%Ni and 82.48%Fe can be prepared with corresponding recovery rates of 96.90%and 95.92%,respectively,when adding 20%low-nickel concentrates.

关键词： Nickel laterite Low-nickel concentrate Nucleating agent Growth kinetics Ni-Fe alloy Direct reduction Magnetic separation

Effects of Process Parameters of Semisolid Stirring on Microstructure of Mg–3Sn–1Mn–3SiC(wt%) Strip Processed by Rheo-rolling

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Acta Metallurgica Sinica(English Letters) 2017年第1期30卷 66-72页

作者： zhan-Yong Zhao Ren-guo Guan Jian-hong zhang Zhou-Yang Zhao Pei-Kang Bai School of Materials Science and Engineering North University of China School of Materials Science and Engineering Northeastern University

A novel semisolid stirring and rheo-rolling process for preparing Mg-3Sn-1Mn-3SiC （wt%） composite strips was proposed, and the effects of process parameters of semisolid stirring on microstructures of Mg-3Sn-1Mn-3SiC （wt%） composite strips were investigated. The average grain size and roundness decrease, and the distribution of SiC becomes more homogeneous with the decrease in stirring temperature and the increase in the stirring speed. When the stirring time is increased, the distribution of SiC particles tends to be homogeneous, and the average grain diameter and roundness of α- Mg grain decrease. Under the following process parameters： the stirring temperature at 640 ℃, the stirring speed at 1100 rpm, the stirring time at 30 min and the roll speed at 0.2 m/s, Mg-3Sn-1Mn-3SiC （wt%） strip with a cross-sectional size of 4 mm × 160 mm was prepared. The ultimate tensile strength and elongation of Mg-3Sn-1Mn-3SiC （wt%） composite strip reached 226 ± 6 MPa and （7.4 ± 0.2）%, which are obviously improved in comparison with Mg-3Sn-1Mn （wt%）.

关键词： Mg-matrix composite Rheo-rolling Microstructure Property

Insight into microstructure evolution on anti-corrosion property of Al_(x)CoCrFeNiC_(0.01) high-entropy alloys using scanning vibration electrode technique

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Rare Metals 2023年第10期42卷 3455-3467页

作者： Bo-Kai Liao zhan-Xiang Liang Zhi-Gang Luo Yue Liu Hao-Wei Deng Tao zhang Xing-Peng guo Qi-Sen Ren hong-En Ge School of Chemistry and Chemical Engineering Guangzhou UniversityGuangzhou510006China School of Physics and Materials Science Center of Advanced Functional MaterialsGuangzhou UniversityGuangzhou510006China Joint Institute of Guangzhou University and Institute of Corrosion Science and Technology Guangzhou UniversityGuangzhou510006China Science and Technology Digitization Department China General Nuclear Power CorporationShenzhen518038China Institute of Nuclear Fuel and Materials China Nuclear Power Technology Research InstituteShenzhen518031China Hubei Key Laboratory of Material Chemistry and Service Failure School of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan430074China

The effect of micro structure on the corrosion resistance of Al_(x)CoCrFeNiC_(0.01)(x=0.2,0.7,and 1.2)high-entropy alloys(HEAs) was systematically studied in this work.The microstructure evolution by regulating the Al content was analyzed in detail.Corrosion behavior was in situ monitored using the scanning vibration electrode technique,as well as some traditional electrochemical measurements.It is interesting to find that the compositions of body-centered cubic(bcc) and face-centered cubic(fcc)phases changed with the rising Al content,while the corresponding electrochemical responses for both phases were discriminated using the scanning Kelvin probe force microscopy method.Cr element was mainly distributed in the bcc phase for Al0.2(x=0.2) alloy,while its distribution changed to the fcc phase for the A10.7 and Al1.2alloys.The micro-galvanic corrosion cells formed between Cr-depleted and Cr-rich phases,resulting in the localized corrosion behaviors for the Al_(x)CoCrFeNiC_(0.01) HEAs,and the order for anti-corrosion property was Al0.2>Al1.2> Al0.7 HEAs.

关键词： High-entropy alloy Corrosion Mechanical property Scanning vibration electrode technique