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Microstructure Evolution of a Cold-rolled 25Cr-7Ni-3Mo-0.2N Duplex Stainless Steel during Two-step Aging Treatments

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Acta Metallurgica Sinica(English Letters) 2013年第5期26卷 517-522页

作者： Tian LIANG Xiaoqiang HU xiuhong kang Dianzhong LI Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences

A cold-rolled 25Cr-7Ni-3Mo-0.2N duplex stainless steel（DSS） has been aged in two steps. Firstly, the aging treatment at interval of 50℃ in a temperature range from 900 to 1050℃ was carried out in order to obtain fine grains. Secondly, another aging treatment at 850℃ was performed to reveal the σ-phase precipitation behavior. A detailed microstructure evolution during those two aging steps was observed by the optical microscope（OM）, the scanning electron microscope（SEM）, the electron backscatter difraction（EBSD） and the transmission electron microscope（TEM）. The results revealed that the micro-duplex structure with grain size of lower than 10 μm appeared after the first aging step. However, their grain size was rapidly increased with increasing aging temperature. Meanwhile, the δ → γ and/or δ → γ ＋ σ transformations took place in association with the occurrence of the extensive recovery or a little recrystallization in δ-grains. During the second aging treatment, σ-phase mainly nucleated at δ/γ interfaces and further grew along those interfaces into various morphologies（e.g., butterfly and granule）. A novel precipitation behavior was found in this study that the γ-grain boundaries bulged not only into the δ-grains as usual, but abnormally into the σ-phase precipitates without the prior precipitation of the isolated secondary austenite γ2or another phases.

关键词： Duplex stainless steel Microstructure evolution Sigma phase Aging treatment Micro-duplex structure

Numerical Simulation of Stress and Deformation for a Duplex Stainless Steel Impeller during Casting and Heat Treatment Processes

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Journal of Materials Science & Technology 2008年第3期24卷 364-368页

作者： Lugui CHEN Yong LING xiuhong kang Lijun XIA Dianzhong LI Shenyang National Laboratory for Materials Science Institute of Metal Research Shenyang 110016 China WTCM Foundry Center Zwijnaarde Belgium

A large-scale, thin wall duplex stainless steel impeller with complex geometry was deformed severely and unpredictably during casting and heat treatment processes resulted in dimensional failure for the final part. In this paper, the distortion of the impeller during casting and heat treatment was calculated. A commercial software, Experto-ViewCast, was used to simulate the transient heat transfer, solidification and mechanical behaviors during the casting and the heat treatment process. The coupled set of governing differential equations for mass, energy and mechanical balance were solved by finite control volume and finite element method. A thermoelastic-visco-plastic rheological model was used to compute the constrained shrinkage of the casting. At each time increment, a coupling of the heat transfer and mechanics was performed. Comparison of the experimental measurements with the model predictions showed good agreement. From the calculated displacements of key points of the blade, the proper inverse displacements were determined to provide an optimum casting pattern and to achieve a uniform and reasonable machining allowance for both faces of the blade.

关键词： Numerical simulation Impeller casting Heat treatment Distortion Modeling

Chemical Compositions,Microstructure and Mechanical Properties of Roll Core used Ductile Iron in Centrifugal Casting Composite Rolls

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Journal of Materials Science & Technology 2012年第9期28卷 853-858页

作者： Yunlong Bai Yikun Luan Nannan Song xiuhong kang Dianzhong Li Yiyi Li Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

The industrial manufacture processes of three kinds of roll core used ductile irons have been investigated via systematical experiments. EfFects of the ratio of C/Si, pig iron, nodularizer and alloying method on the microstructure and mechanical properties of the heavy section ductile iron have been analyzed. It has been found that when treated with RE-Mg plus Sb, high quality nodular castings can be produced even if much anti spheroidizing alloy elements are included in the pig iron. The alloy element Sb played an important role in the control of graphite morphology.

关键词： Centrifugal casting Roll Heavy section ductile iron Micro-alloying with Sb

Numerical Simulation of Solidification of Work Roll in Centrifugal Casting Process

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Journal of Materials Science & Technology 2012年第2期28卷 147-154页

作者： Nannan Song Yikun Luan Yunlong Bai Z.A. Xu xiuhong kang Dianzhong Li Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China SIRRIS the Collective Center for the Belgian Technological Industry Technologiepark 915 9052 Zwijnaarde Belgium

A program on the solidification process of horizontal centrifugal casting coupled with eutectic carbides segregation has been developed in this paper. Due to the geometrical features of work roll, a cylindrical coordinate system was used. The temperature field of the outer layer at the end of filling process was imported as the initial temperature condition for the solidification process. The model of eutectic carbides segregation caused by different densities between eutectic MC and the molten steel was coupled in the program. The temperature field of the outer layer of work roll during horizontal centrifugal casting process was investigated. Results show that the outer layer has a ＂sandwich shape＂ solid fraction manner. Results also indicate that the segregation of eutectic MC is quite severe during centrifugal casting process. It forms four zones of different content of carbides in radial direction. The simulated results of MC carbides segregation phenomenon agree with the experimental observations.

关键词： Numerical simulation Horizontal centrifugal casting MC segregation Work roll

Formation mechanism of shrinkage and large inclusions of a 70t 12Cr2Mo1 heavy steel ingot

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China Foundry 2014年第1期11卷 46-51页

作者： Liu Hongwei Fu Paixian kang xiuhong Ma Xiaoping Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences

Shrinkage cavities and large inclusions are serious internal defects of heavy steel ingot and influence the quality of subsequent forgings. In order to remove these two types of defects, a 70 t 12Cr2Mo1 heavy ingot fabricated by vacuum carbon de-oxidation process was sectioned and investigated by means of structure observation and EDS analysis. To further study the forming mechanism of shrinkage and inclusion defects and find possible solutions, simulation on pouring and solidification processes was also carried out using Fluent and ProCAST software, respectively. Results show that the shrinkage defects do not appear in the middle-upper part of the ingot. The critical value of shrinkage cavity criterion is ascertained as 0.013 on the basis of sectioning investigation and simulation results, which can be used in computer simulation to predict and avoid shrinkage defects in production of 12Cr2Mo1 ingots with different weights. However, large inclusions are found at the bottom of the ingot body. The bad thermal conditions of the ingot surface and large amount of entrained slag are the main origin of the large inclusions. The simulation result of the pouring process shows that large inclusions may be eliminated by combined measures of improving the top thermal condition and controlling the height of rudimental molten steel in the ladle to above 300 mm.

关键词： 12Cr2Mo1 heavy ingot segregation shrinkage defect large inclusions

Computer simulation of core filling process of cast high speed steel roll

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China Foundry 2009年第4期6卷 314-318页

作者： Song Nannan Luan Yikun Bai Yunlong kang xiuhong Xia Lijun Li Dianzhong Shenyang National Laboratory for Material Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

Core filling process of cast high speed steel roll was simulated.Ductile iron was used as core material.The influences of filling parameters,such as core filling time and core filling temperature,on the filling process were investigated.Based on the simulated results,optimal core filling parameters were determined.The predicted temperature fields show that the temperature at the roll shoulder is the lowest during the core filling process and usually causes binding defects there.Method for solving this problem was presented.

关键词：高速钢轧辊计算机模拟铸造工艺填补灌装过程核心温度数值模拟球墨铸铁

Qingre Jianpi decoction(清热健脾汤)attenuates inflammatory responses by suppressing NOD-like receptor family pyrin domain-containing 3 inflammasome activation in dextran sulfate sodium-induced colitis mice

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Journal of Traditional Chinese Medicine 2021年第1期41卷 68-78页

作者： ZHANG Jiayan kang xiuhong SUN Mengyun ZHANG Shengsheng Department of Digestive System Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical UniversityBeijing 100010China Department of Digestive system Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical UniversityBeijing 100010China

OBJECTIVE:To investigate the effects of Qingre Jianpi decoction(清热健脾汤,QRJPD)on dextran sulfate sodium(DSS)-induced colitis mice and explore its mechanism.METHODS:All mice were randomly divided into six groups.Weight changes,disease activity index values,and histological damage were detected.Inflammatory cytokines and immune cell infiltration were measured using enzyme-linked immunosorbent assays(ELISA)and immunohistochemistry(IHC)method.The key protein expression levels of the NOD-like receptor family pyrin domain-containing 3(NLRP3)inflammasome were detected by western blot analysis,IHC,and quantitative reverse transcription polymerase chain reaction.RESULTS:QRJPD played an anti-inflammatory role in the treatment of ulcerative colitis(UC),reduced the secretion of inflammatory cytokines,and inhibited the inflammatory infiltration of immune cells by suppressing DSS-induced activation of the NLRP3 inflammasome.CONCLUSION:QRJPD exerts protective effects by inhibiting DSS-induced NLRP3 inflammasome activation.

关键词： Colitis,ulcerative anti-inflammatory agents NLR family,pyrin domain-containing 3 protein inflammasomes

The effect of traditional Chinese medicine rehabilitation exercise(pulmonary Daoyin)in patients with chronic obstructive pulmonary disease:A systematic review and meta-analysis

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Journal of Integrative Nursing 2024年第1期6卷 3-14页

作者： Yuyin CHEN Yuhua QIU Kaimin ZHOU Ruyi TAN Wanlin PENG xiuhong LONG Meijiang CHEN School of Nursing Guangxi University of Chinese MedicineNanningChina Department of Respiratory Disease Ruikang Hospital Affiliated to Guangxi University of Chinese MedicineNanningChina Department of Nursing Ruikang Hospital Affiliated to Guangxi University of Chinese MedicineNanningChina

Objective:Previous research has demonstrated that pulmonary Daoyin could be an efficacious way to ameliorate the physical and psychological state of sufferers with chronic obstructive pulmonary disease(COPD)and bolster the quality of life.However,the results are not consistent.Thus,the objective of this research is to assess the impacts of pulmonary Daoyin in individuals with COPD.Methods:Relevant articles were searched in Web of Science,Cochrane Library,PubMed,EMBASE,SinoMed,CNKI,Wanfang,and VIP from database inception to January 2024.Results:There were a total of 15 randomized controlled trials(RCTs)included in this meta-analysis involving 1732 patients,of which 864 participated in the intervention group and 868 in the control group.When comparing with the control group,the COPD patients practicing pulmonary Daoyin demonstrated a significant improvement in 6 min walking distance(mean difference[MD]=24.53,95%confidence interval[CI][18.55,30.52],P<0.00001),forced expiratory volume in the 1 s(FEV_(1))(MD=0.39,95%CI[0.18,0.59],P=0.0002),percentage of FEV_(1)to the predicted value(FEV_(1)%)(MD=5.35,95%CI[3.22,7.48],P<0.0001),the forced vital capacity(FVC)(MD=0.39,95%CI[0.06,0.73],P=0.02),percentage of FVC to the predicted value(FVC%)(MD=7.52,95%CI[4.91,10.13],P<0.00001),the ratio of FEV_(1)/FVC(MD=4.95,95%CI[0.91,8.99],P=0.02),peak expiratory flow rate(standardized MD=0.98,95%CI[0.74,1.22],P<0.00001),modified Medical Research Council(mMRC)scale(MD=-0.47,95%CI[-0.89,-0.04],P=0.03),and Borg scale(MD=-0.65,95%CI[-0.75,-0.55],P<0.00001).Conclusions:Our findings may illuminate the influence of pulmonary Daoyin on exercise ability,breathlessness,and pulmonary function in COPD patients.More rigorous RCTs with larger samples and longer-term interventions will be required moving forward.

关键词： Chronic obstructive pulmonary disease exercise capacity meta-analysis pulmonary Daoyin pulmonary function rehabilitation

Highly ordered crystallization ofα-FAPbl_(3) films via homogeneous seeds for efficient perovskite solar cells

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Journal of Energy Chemistry 2024年第7期94卷 625-634页

作者： Guohui Luo Linfeng Zhang Liyun Guo xiuhong Geng Penghui Ren Yi Zhang Haihua Hu Xiaoping Wu Lingbo Xu Ping Lin Haiyan He Xuegong Yu Peng Wang Can Cui Key Laboratory of Optical Field Manipulation of Zhejiang Province Department of PhysicsZhejiang Sci-Tech UniversityHangzhou 310018ZhejiangChina Zhejiang Provincial Key Laboratory of Fiber Materials and Manufacturing Technology Zhejiang Sci-Tech UniversityHangzhou 310018ZhejiangChina Hangzhou City University Hangzhou 310015ZhejiangChina Key Laboratory of Solar Energy Utilization and Energy Saving Technology of Zhejiang Province Zhejiang Baima Lake Laboratory Co.Ltd.Hangzhou 310012ZhejiangChina State Key Laboratory of Silicon Materials and School of Materials Science and Engineering Zhejiang UniversityHangzhou 310027ZhejiangChina

Formamidine lead triodide(FAPbI_(3))perovskites have become the most promising photovoltaic materials for perovskite solar cells with record power conversion efficiency(PcE).However,random nucleation,phase transition,and lattice defects are still the key challenges limiting the quality of FAPbI_(3)films.Previous studies show that the introduction or adding of seeds in the precursor is effective to promote the nucleation and crystallization of perovskite films.Nevertheless,the seed-assisted approach focuses on heterogeneous seeds or hetero-composites,which inevitably induce a lattice-mismatch,the genera-tion of strain or defects,and the phase segregation in the perovskite films.Herein,we first demonstrate that high-quality perovskite films are controllably prepared usingα-and δ-phases mixed FAPbI_(3) micro-crystal as the homogeneous seeds with the one-step antisolvent method.The partially dissolved seeds with suitable sizes improve the crystallinity of the perovskite flm with preferable orientation,improved carrier lifetime,and increased carrier mobility.More importantly,theα-phase-containing seeds promote the formation of α-phase FAPbI_(3) films,leading to the reduction of residual lattice strain and the suppres-sion of I-ion migration.Besides,the adding of dimethyl 2,6-pyridine dicarboxylate(DPD)into the pre-cursor further suppresses the generation of defects,contributing to the PCE of devices prepared in air ambient being significantly improved to 23.75%,among the highest PCEs for fully air-processed FAPbl_(3) solar cells.The unpackaged target devices possess a high stability,maintaining 80%of the initial PCE under simulated solar illumination exceeding 8o0 h.

关键词： Perovskite solar cells FAPbI_(3) Homogeneous seeds Strain Phase stability