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EFFECT OF heating rate ON THERMO-INDUCED AGGREGATION OF POLY(ETHYLENE OXIDE)-b-POLY(N-ISOPROPYLACRYLAMIDE) IN AQUEOUS SOLUTIONS

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Chinese Journal of Polymer Science 2010年第3期28卷 437-447页

作者：梁德海 Beijing National Laboratory for Molecular Sciences and the Key Laboratory of Polymer Chemistry & Physics of Ministry of Education College of Chemistry & Molecular EngineeringPeking University

The effects of heating rate on the aggregate behavior of poly（ethylene oxide）-b-poly（N-isopropylacrylamide） in aqueous solutions were investigated in detail by laser light scattering and TEM. By employing two separate heating protocols, step-by-step heating at 〈 5 K/step and one-step jump, to heat the sample from 15℃ to the selected temperature, we found that the heating rate only showed significant effect on the aggregates above the cloud point. The aggregate formed by step-by-step heating exhibited a much larger size and a broader size distribution than those formed by one-step jump heating. Moreover, neither of the aggregates were ideal micellar structures as indicated by the size and the Rg/Rh values. On the contrary, at temperatures below the cloud point where the block copolymer formed core-shelled micelles, the heating rate showed negligible effect on the size and size distribution of the micelles. Since the system underwent a phase separation above the cloud point, the heating rate effect could be reasonably explained by the phase separation mechanisms： the nucleation-and-growth mechanism in the metastable region and the spinodal decomposition mechanism in the unstable region.

关键词： heating rate Cloud point Nucleation-and-growth Spinodal decomposition PEO-b-PNIPAm.

Effects of heating rate on the alloy element partitioning and mechanical properties in equiaxedα+βTi-6Al-4V alloy

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Journal of Materials Science & Technology 2021年第35期94卷 1-9页

作者： Jinhu Zhang Hongtao Ju Haisheng Xu Liang Yang Zhichao Meng Chen Liu Ping Sun Jianke Qiu Chunguang Bai Dongsheng Xu Rui Yang Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Safety Evaluation Center Shenyang Research Institute of Chemical Industry Co.Ltd.Shenyang 110141China

The effects of heating rate on the alloy element partitioning and mechanical properties during the phase transformation ofα→βin Ti-6Al-4 V alloy under solution treatment have been investigated by the experiments and phase field simulations,which reveal the evolutions of microstructure and compositions at the non-equilibrium state and well verify the experimental *** specific results indicate that the compositions measured through electron probe micro-analysis(EPMA)under a lower heating rate are close to the equilibrium ones corresponding to the solution *** up to the target solution temperature,as the heating rate increases,the Al content decreases and V increases in the primaryα(α_(p))grain with a larger size,the volume fraction ofα_(p)increases and the composition gradient betweenα_(p)andβphases gets *** interrelated relationship among the diffusion,compositions,solution temperature and free energy of the system has been discussed in ***,increasing the heating rate(~20.0 K/min)may help to improve the mechanical properties of the alloy by mainly adjusting theα_(p)/β;volume fractions,α_(p)particle size and secondaryα(α_(p))size during the process of heating up to the solution *** results may shed some light on the optimization of the knowledge-based heat treatment route.

关键词： heating rate Alloying element partitioning Microstructure morphology Mechanical properties

Gas release characteristics during carbonization of iron coke hot briquette and influence of heating rate

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Journal of Iron and Steel Research International 2023年第11期30卷 2163-2172页

作者： Zi-yu Wang Dong Han Zheng-gen Liu Man-sheng Chu Yong-jie Zhang Li-feng Zhang Ji-wei Bao Ming-yu Wang School of Metallurgy Northeastern UniversityShenyang110819LiaoningChina Engineering Research Center of Frontier Technologies for Low-Carbon Steelmaking(Ministry of Education) Shenyang110819LiaoningChina Liaoning Province Engineering Research Center for Technologies of Low-Carbon Steelmaking Shenyang110819LiaoningChina

The release characteristics of CH_(4),H_(2),CO and CO_(2) from iron coke hot briquette(ICHB)during carbonization were *** results show that compared with briquette without iron ore,Fe_(3)O_(4) can inhibit the release rate of H2 and promote the production of CO and CO_(2).In addition,when the heating rate increases from 3 to 7℃/min,the release rates of CH4 and H2 increase,while the release rates of CO and CO_(2) first increase and then *** carbonization process of ICHB was segmented,and corresponding kinetic analysis was carried *** results show that the activation energy of StageⅡand StageⅣis higher in the carbonization process of ICHB,and the active pyrolysis of coal and the reduction of iron ore occur in these two *** addition,the effect of heating rate on the kinetic parameters of ICHB carbonization process was *** was found that when the heating rate increased,the reaction activation energy of StageⅣdecreased first and then increased,which was consistent with the release law of CO and CO_(2).The analysis showed that the increase in heating rate leads to more reactions at higher temperatures,resulting in an increase in the release rate of some *** addition,thermal hysteresis can also cause some processes to fail to fully react at the end of *** is also found that the apparent activation energy and preexponential factor have kinetic compensation effect during the car-bonization of ICHB.

关键词： Iron coke hot briquette Carbonization Gas release characteristic heating rate Kinetics

Effect of heating rate on Microstructure Evolution and Magnetic Properties of Cold Rolled Non-Oriented Electrical Steel

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Journal of Iron and Steel Research International 2010年第11期17卷 54-61页

作者： WANG Jian LI Jun WANG Xin-feng TIAN Jian-jun ZHANG Cai-hong ZHANG Shen-gen School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Research Institute Baoshan Iron and Steel Co Ltd Shanghai 200900 China Beijing Vocational College of Electronic Science Beijing 100026 China

The effects of heating rate （ranging from 50 to 300 ℃/s） during the final annealing process on microstructure evolution and magnetic properties of cold rolled non-oriented electrical steel were investigated. It was found that increasing heating rate increased the nucleation temperature and complete recrystallization temperature. At the same time, heating rate increasing could cause the substantially refined structures for the recrystallization grains and this grain refinement would decline when the heating rate was beyond 50 ℃/s. The recrystallization texture exhibited pronounced improvement with heating rate, such as the intensity decrease of 〈111〉//ND （normal direction） fiber and the intensity increase of { 110}%〈001〉 Goss texture component. The texture improvement and grain size refinement caused by heating rate increasing resulted in complicated variation of the magnetic properties. The magnetic induction （B50） keeps increasing while heating rate increases from 15 to 300 ℃/s which is due to the recrystallized texture optimization caused by rapid heating. The core losses （P1.5/50） decrease while heating rate increases from 15 to 100 ℃/s; however, the core losses would increase when heating rate is higher than 100 ℃/s, which is caused by the mean grain size refinement after rapid heating annealing. The results indicate that recrystallization texture and the magnetic properties of the non-oriented electrical steel can be improved definitely by rapid heating during the final annealing treatment.

关键词： non-oriented electrical steel heating rate texture core loss magnetic induction

Effect of temperature and heating rate on mechanical properties of magnesium alloy AZ31

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Transactions of Nonferrous Metals Society of China 2010年第B07期20卷 426-429页

作者：袁权陈斌罗吉张丁非权国政 College of Resources and Environmental Science Chongqing University Key Laboratory for Exploitation of Southwest Resources and Environmental Disaster Control Engineering Ministry of EducationChongqing University College of Materials Science and Engineering Chongqing University

Effects of temperature and heating rate on the mechanical properties of the tensile specimens of magnesium alloy AZ31 were experimentally investigated using a Gleeble-1500 thermo-mechanical material testing *** metallurgraphs of the fracture section of the specimens were also experimentally observed and analyzed for exploring their failure mechanism under different temperatures and heating *** results show that the higher the temperature,the lower the ultimate strength of the *** the higher the heating rate,the higher the ultimate strength of the *** high temperatures and high heating rates will induce microvoids in the specimens which make the specimens failure under relatively low loads.

关键词： AZ31 magnesium alloy temperature heating rate strength plasticity

A FINITE-ELEMENT FORMULATION OF heating rate AND SKIN FRICTION ON THE BASIS OF CONSERVAION LAWS

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Acta Mechanica Sinica 2000年第2期16卷 128-132页

作者：段占元童秉纲姜贵庆 Graduate School University of Science & Technology of China Beijing China 100039 Beijing Institute of Aerodynamics Beijing China 100074

In the framework of the finite element method (FEM), a prediction method for the heating rate and the skin friction on a body surface is presented by using the energy and momentum conservation equations respectively. ... 详细信息

关键词： conservation equations heating rate skin friction weighted functions

Effect of heating rate Before Tempering on Reversed Austenite in Fe-9Ni-C Alloy

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Journal of Iron and Steel Research International 2012年第9期19卷 73-78页

作者： ZHANG Kun , TANG Di , WU Hui-bin ( National Engineering Research Center of Advanced Rolling , University of Science and Technology Beijing , Beijing 100083 , China ) National Engineering Research Center of Advanced Rolling University of Science and Technology Beijing Beijing China

The alloy was reheated to 580℃ for tempering at rates of 2 , 5 , 10 , 20 , and 40℃ / s , respectively , after *** amount , distribution , and stability of reversed austenite were investigated by X-ray diffraction ( XRD ) and electron back scatter diffraction ( EBSD ) .The microstructure and cryogenic impact energy were studied by scanning electron microscope ( SEM ), transmission electron microscope ( TEM ) and Charpy V-notch ( CVN ) *** results showed that when the sample was heated at 10℃ / s , the volume fraction of reversed austenite exhibited maximum of 8% ; the reversed austenite was uniform along all kinds of boundaries ; the reversed austenite contained higher concentration of carbon which enabled it to be more *** cryogenic toughness of the alloy was greatly improved when heated at 10℃ / s , as the fracture surface observation showed that it mainly fractured in ductile rupture mode , which was consistent with the results of cryogenic impact energy.

关键词： 9Ni steel heating rate reversed austenite cryogenic toughness

Microstructural evolution and mechanism of grain growth in magnesia ceramics prepared by high pressure and temperature with ultra-high heating rate

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Science China(Technological Sciences) 2014年第6期57卷 1085-1092页

作者： LIU JiangHao FU ZhengYi WANG WeiMin ZHANG JinYong WANG Hao WANG YuCheng LEE SooWohn NIIHARA Koichi State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Department of Environmental Engineering Sun Moon University Extreme Energy-Density Research Institute Nagaoka University of Technology1603-1 KamitomiokaNagaokaNiigata 940-2188Japan

The fast densification method of combustion reaction plus quick pressing was adopted to prepare nanocrystalline *** densification process of magnesia compact with a particle size of 100 nm was investigated,under the applied pressure of up to 170 MPa,and the temperature range of 1740–2080 K with ultra-high heating rate(above 1700 K/min).High-purity magnesia ceramics with a relative density of 98.8%and an average grain size of 120 nm was obtained at 1740 K,and the grain growth during the densification process was effectively *** characteristic morphology of evaporation-condensation was observed in the compact prepared at 2080 K,which revealed the actual process of mass transfer by gas ***,the investigation on the microstructure evolution and mechanism of grain growth was carried out,on the basis of as-preserved nanocrystalline *** result indicated that the grain growth of the nanocrystalline MgO was controlled by the mechanism of evaporation-condensation rather than surface ***,the pressure had an influence of restraining the grain growth based on solid diffusion and strengthening the effect of gas diffusion with the increasing *** the particular conditions,there existed an appropriate temperature for the densification of nanocrystalline magnesia,while the excessive temperature would exaggerate grain growth and impede densification.

关键词： grain growth densification heating rate evaporation-condensation surface diffusion nanocrystalline ceramics

Decline of nucleation in the heating process with a high heating rate

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Chinese Physics B 2014年第8期23卷 426-429页

作者：杨高林林鑫宋梦华胡桥汪志太黄卫东 State Key Laboratory of Solidification Processing Northwestern Polytechnical University

The effect of the heating rate on the nucleation of metallic glass in a rapid heating process starting from the glass transition temperature is investigated. The critical nucleus radius increases with the increase of the temperature of the undercooling liquid. If the increment rate of the critical nucleus radius, owing to the heating process, is higher than the growth rate of the nuclei, the nuclei generated at the low temperature will become the embryos at the high temperature. This means that the high heating rate can make no nucleation happen in the heating process. In consideration of the interfacial energy, the growth rate of the nuclei increases with the increase of their size and the growth rate of the critical nucleus is zero. Thus, the lower heating rate can also make the nuclei decline partially. Finally, this theory is used to analyze the nucleation process during laser remelting metallic glass.

关键词： nucleation growth rate heating rate bulk metallic glass