检索结果-南通市图书馆

Melt flow,heat transfer and solidification in a flexible thin slab continuous casting mold with vertical-combined electromagnetic braking

引用

Journal of Iron and Steel Research(International) 2024年第2期31卷 401-415页

作者： Lin Xu Ze-feng Han Christian Karcher En-gang Wang Key Laboratory of Electromagnetic Processing of Materials(Ministry of Education) Northeastern UniversityShenyang110819LiaoningChina Key Laboratory of Liaoning Province for Clean Combustion Power Generation and Heating Technology Shenyang Institute of EngineeringShenyang110136LiaoningChina Institute of Thermodynamics and Fluid Mechanics Technische Universität IlmenauIlmenau98684Germany

During continuous casting of steel slabs,the application of electromagnetic braking technology(EMBr)provides an effective tool to influence solidification by controlling the pattern of melt flow in the mold.Thus,the quality of the final product can be improved considerably.A new electromagnetic braking(EMBr)method,named vertical-combined electromagnetic braking(VC-EMBr),is proposed to be applied to a flexible thin slab casting(FTSC)mold.To evaluate the beneficial effects of the VC-EMBr,the melt flow,heat transfer,and solidification processes in the FTSC mold are studied by means of numerical simulations.In detail,a Reynolds-averaged Navier–Stokes turbulence model together with an enthalpy-porosity approach was used.The numerical findings are compared with respective simulations using the traditional Ruler-EMBr.The results demonstrate that the application of the VC-EMBr contributes significantly to preventing relative slab defects.In contrast to the Ruler-EMBr,the additional vertical magnetic poles of the VC-EMBr preferentially suppress the direct impact of jet flow on the narrow face of FSTC mold and considerably diminish the level fluctuation near the meniscus region.For instance,by applying a magnetic flux density of 0.3 T,the maximum amplitude of meniscus deflection reduces by about 80%.Moreover,the braking effect of the VC-EMBr effectively improves the homogeneity of temperature distribution in the upper recirculation region and increases the solidified shell thickness along the casting direction.On this basis,the newly proposed VC-EMBr shows a beneficial effect in preventing relative slab defects for FTSC thin slab continuous casting.

关键词： Electromagnetic braking Mold Melt flow Heat transfer solidification

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Multi-physical fields distribution in billet during helical electromagnetic stirring:A numerical simulation research

引用

China Foundry 2024年第1期21卷 51-59页

作者： Dong Pan Qing-tao Guo Kai-lun Zhang Fu-zhi Yu Yu-ying Li Yu-bao Xiao State Key Laboratory of Metal Materials for Marine Equipment and Application Anshan 114009LiaoningChina Ansteel Beijing Research Institute Co. Ltd.Beijing 102200China

Electromagnetic stirring is one of the widely applied techniques to modify the quality of casting billets.Different from conventional rotate stirring,the helical stirring is more professional in assisting multi-dimensional flow of molten metal and eliminating solidification defects.In this study,the single-winding helical stirring(SWHS)was introduced,offering advantages such as smaller volume and lower electromagnetic shielding compared to traditional helical stirring methods.Following a comprehensive numerical simulation,the stirring parameters of SWHS were adjusted to yoke inclination angle of 43°and frequency of 12 Hz.The higher electromagnetic force and flow velocity in drawing direction,as well as the lower temperature gradient induced by the SWHS,are positive factors for homogeneous solidification of billet.The experimental results on Al-8%Si alloy and 0.4%C-1.1%Mn steel demonstrate that compared to rotate stirring,the SWHS process can induce better billet quality and is more effective in accelerating the equiaxed expansion and reducing element segregation.The SWHS process can enhance the equiaxed ratio of the billet by 58.3%and reduce segregation degree of carbon element by 10.97%.Consequently,SWHS holds great promise as a potential approach for improving the quality of continuous casting billets.

关键词： billet electromagnetic stirring helical solidification element segregation numerical simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Improvement for creep strength of a second-generation single crystal superalloy by design of heat treatments

引用

Rare Metals 2024年第1期43卷 342-350页

作者： Wan-Shun Xia Xin-Bao Zhao Jia-Chen Xu Quan-Zhao Yue Qing-Qing Ding Huan-Chang Duan Yue-Feng Gu Hong-Bin Bei Ze Zhang Institute of Superalloys Science and Technology School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China State Key Laboratory of Silicon and Advanced Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China

Design of heat treatments is related to the key technology for development of nickel-based single crystal superalloys(Ni-SXs). Based on the full understanding of the solidification characteristics, this work applies optimization design of heat treatments for a second-generation Ni-SX. Microstructure evolution and creep properties are compared in the material under conventional/standard(Std.) and optimized(Opt.) treatments. For the Std. sample,strong dendritic segregations determine inconsistent microstructure evolution in the dendritic(D) and interdendritic region(ID), while the latter serves as weak area to have the prior microcrack initiation, damaging overall performance of the alloy. The Opt. treatment applies higher homogenization temperature, leading to overall reduced segregations, while not inducing incipient melting. A lower temperature of first-step ageing is used to lower the size ofγ'particles. These help to form the more uniform microstructure in dendritic and interdendritic region and relieve the inconsistent microstructure evolution. The balanced local strength makes ID no longer as the weak area,thus restricting microcrack initiation. Great improvement of high temperature and low stress property is obtained by this progress, leading to the pronounced increase of creep rupture life under 1100 °C/140 MPa.

关键词： Single crystal superalloy Heat treatment Segregation solidification Creep property

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

solidification and heat transfer of molten steel slag particles during air quenching process

引用

Journal of Iron and Steel Research(International) 2023年第9期30卷 1834-1842页

作者： Wen-feng Gu Jiang Diao Rui-xin Hu Wen-sun Ge Wen-feng Tan Hong-yi Li Bing Xie College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Chongqing Key Laboratory of Vanadium–Titanium Metallurgy and Advanced Materials Chongqing UniversityChongqing 400044China Institute of Materials Engineering Technology Pangang Group Research Institute Co.Ltd.Panzhihua 617000SichuanChina

In order to effectively utilize the resources and energy of molten steel slag,the variation of precipitation phase and specific heat of air quenched steel slag(AQSS)particles during continuous cooling process was investigated by FactSage and thermogravimetry differential scanning calorimetry.The cooling and solidification process of molten AQSS particles was simulated by Fluent.The microstructure changes in AQSS particles in solidification process were analyzed using an ultrahigh temperature laser confocal microscope and a scanning electron microscope.The results indicated that in the cooling process of molten AQSS particles,the precipitation of Ca_(2)Fe_(2)O_(5) resulted in the largest change of specific heat.Under the condition of slow cooling,the cooling rate is more obviously affected by specific heat.When the initial air velocity was 300 m s^(-1),there was the highest temperature difference in AQSS particles during cooling process.What is more,the compactness of the boundary region of AQSS particles was obviously better than that of its central region.

关键词： Specific heat Air quenched steel slag Cooling solidification Microstructure change

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

solidification microstructure of Ti-43Al alloy by twin-roll strip casting

引用

China Foundry 2023年第2期20卷 99-107页

作者： Yang Chen Guo-huai Liu Ye Wang Zhao-dong Wang State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China College of Material Science and Chemical Engineering Harbin University of Science and TechnologyHarbin 150080China

As a near-net-shape technology,the twin-roll strip casting(TRC)process can be considered to apply to the fabrication of TiAl alloy sheets.However,the control of the grain distribution is very important in strip casting because the mechanical properties of strips are directly determined by the solidification microstructure.A three-dimensional(3D)cellular automation finite-element(CAFE)model based on ProCAST software was established to simulate the solidification microstructure of Ti-43Al alloy.Then,the influence of casting temperature and the maximum nucleation density(nmax)on the solidification microstructure was investigated in detail.The simulation results provide a good explanation and prediction for the solidification microstructure in the molten pool before leaving the kissing point.Experimental and simulated microstructure show the common textureorientation in the columnar grains zone.Finally,the microstructure evolution of the Ti-43Al alloy was analyzed and the solidification phase transformation path during the TSC process was determined,i.e.,L→L+β→β→β+α→α+γ+β/B2 phase under a faster cooling rate and L→L+β→β→β+α→γ+lamellar(α_(2)+γ)+β/B2 phase under a slower cooling rate.

关键词： TiAl alloy simulation microstructure strip casting solidification

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

solidification segregation behavior of Nb-containing 310S steel

引用

Journal of Iron and Steel Research(International) 2023年第1期30卷 82-87页

作者： Yu-tuo Zhang Hao Zou School of Materials Science and Engineering Shenyang Ligong UniversityShenyang 110159LiaoningChina Institute of Metal Research Chinese Academy of SciencesShenyang 110016LiaoningChina

The solidification characteristics and segregation behavior of solute elements Nb,Ni,Mn,Si,Cr and C in 0.3 wt.%Nb-310S steel were investigated using the isothermal solidification quenching experiment and Thermo-Calc calculation.The phase transformation for 0.3%Nb-310S steel under equilibrium condition can be summarized as follows:liquid(L)→L+γ(1406℃)→γ(1334℃)→γ+NbC(1322℃)→γ+NbC+M_(23)C_(6)(1006℃)→γ+NbC+M_(23)C_(6)→σ(755℃).The results showed that the solidification began with the formation of primary austenite dendrite.The volume fraction of the liquid phase decreased rapidly as the temperature decreased in the initial solidification stage,and then,the liquid phase fraction decreased slowly.When austenite formed,Mn and Ni were enriched in the solid phase,while Nb and C were rejected into the liquid.Nb was present the highest segregation coefficient in 0.3%Nb-310S austenitic stainless steel.The segregation of Nb was the most serious,followed by Mn,Ni and C.Cr and Si exhibited slight segregation during the solidification.The solidification was terminated by the formation of NbC phase.

关键词： 310S steel Nb solidification Segregation Thermo-Calc calculation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

solidification in a shell-and-tube thermal energy storage unit filled with longitude fins and metal foam:A numerical study

Energy and Built Environment

引用

Energy and Built Environment 2023年第1期4卷 64-73页

作者： Xiaohu Yang Fengfei Xu Xinyi Wang Junfei Guo Ming-Jia Li Institute of the Building Environment&Sustainability Technology School of Human Settlements and Civil EngineeringXi’an Jiaotong UniversityXi’an 710049China Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an 710049China Shanghai Industrial Boiler(Wuxi)CO. LTD.Wuxi 214000China

In this study,an innovative thermal energy storage design method was developed by adding the combination of metal foam and fin to phase change materials(PCMs).A numerical model was built and verified based on the comparison among the present model prediction,experimental measurements,and numerical results in open lit-erature.To highlight the novel design method,four cases including fin-PCM,foam-PCM,fin-foam-PCM,and PCM unit were compared by means of solidification features.The temperature distribution,solidification front propa-gation,and buoyancy-induced convection in the liquid PCM were accounted for.Numerical results demonstrated that metal foam outperformed fin regarding the improvement on solidification phase change.The combination of foam and fin achieved the best performance,leading to a 90.5%reduction in complete energy release time in comparison with the PCM unit.The proposed design method provided reference potentials for advancing energy storage engineering.However,buoyancy-induced convection in the liquid PCM before solidification was harmful to the formation of solidification front and its movement.A maximal 11.5%prolonging time for the complete solidification was found.

关键词： Thermal energy storage Phase change materials Metal foam Shell and tube heat exchanger solidification

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A review of the origin of equiaxed grains during solidification under mechanical stirring,vibration,electromagnetic,electric-current,and ultrasonic treatments

引用

Journal of Materials Science & Technology 2023年第13期144卷 243-265页

作者： Nagasivamuni Balasubramani Jeffrey Venezuela David StJohn Gui Wang Matthew Dargusch Centre for Advanced Materials Processing and Manufacturing(AMPAM) School of Mechanical and Mining EngineeringUniversity of QueenslandSt.LuciaQLD 4072Australia

Refinement of grains and intermetallic phases in the as-solidified alloy structure offers uniform struc-tural properties,eliminates or minimizes common solidification defects,including segregation and hot cracking,and improves thermomechanical processing of wrought alloys.Melt processing by an external field is an efficient process for achieving refinement of the solidification structure of Al and Mg alloys without altering the alloy composition.A wide range of melt processing methods and solidification stud-ies(conventional,directional,and in-situ approaches)have been reported in the literature that explore the mechanism of refinement.Identifying the dominant grain refinement mechanism has been a focus of most investigations because significant variations exist according to the casting conditions and the type of applied external treatments.The origin of fine grains occurs through either one or a combination of heterogenous nucleation,fragmentation of dendrites and grains formed and then separated from the surface of the melt and mould wall under vibration or agitation.The first part of this review describes the prominent external field techniques and the mechanisms proposed for the origin of fine grains.The second part critically compares the current understanding of these grain refinement mechanisms to de-termine differences and commonalities to identify the factors that promote the formation of equiaxed zones occupying a large volume fraction of the casting.

关键词： Grain refinement solidification Melt processing Equiaxed grains Intermetallic refinement

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Numerical Analysis on solidification Behavior of Graphene Nanoplatelet Based Nanofluid in Cold Storage Cavity

引用

Journal of Thermal Science 2022年第4期31卷 1180-1193页

作者： CHEN Chen FENG Shiyu PENG Hao PENG Xiaotian LIU Weihua College ofAerospace Engineering Nanjing University ofAeronautics and Astronautics Nanjing 210016China Institute of Thermal Engineering Shanghai Maritime UniversityShanghai 201306China

Addition of graphene nanoplatelet(GNP)into water is a promising method for improving cold storage system performance,and its application requires comprehensive understanding of solidification behavior of GNP-water nanofluid.In the present study,the influences of GNP mass concentration,cold storage cavity size and shape on solid-liquid interface evolution,temperature distribution,streamline profile as well as solidification rate are numerically analyzed.The enthalpy-porosity technique is adopted to track solid-liquid interface.The results show that the enhancement effect of GNPs on solidification is mainly reflected in the final stage in which heat conduction is predominant;the solidification occurs at the bottom of cavity in the early stage,and the solid-liquid interface is similar to the shape of cavity itself and then tends to be circular in the middle and final stages respectively;the reduction degree of solidification time reaches 30.1%at GNP mass concentration of 1.2 wt%under present simulation conditions;decreasing cavity size and adopting triangular cavity are beneficial for promoting the solidification,but they will suppress the enhancement effect of GNPs on solidification.

关键词： cavity shape graphene nanofluid phase change material solidification

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Investigation on the solidification and Phase Transformation in Pb-Free Solders Using In Situ Synchrotron Radiography and Diffraction:A Review

引用

Acta Metallurgica Sinica(English Letters) 2022年第1期35卷 49-66页

作者： Guang Zeng Shiqian Liu Qinfen Gu Zebang Zheng Hideyuki Yasuda Stuart D.McDonald Kazuhiro Nogita School of Materials Science and Engineering Central South UniversityChangsha 410083China Nihon Superior Centre for the Manufacture of Electronic Materials(NS CMEM) School of Mechanical and Mining EngineeringThe University of QueenslandBrisbaneQLD 4072Australia Graduate School Shenzhen Technology UniversityShenzhen 515118China Australian Synchrotron ANSTO.800 Blackburn RdClaytonVIC 3168Australia State Key Laboratory of solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Department of Materials Science and Engineering Kyoto UniversitySakyo‑kuKyoto 606‑8501Japan

It is widely accepted that further development of Pb-free solder alloys for improved processing and in-service properties of next-generation electronics,can be accelerated through a fundamental understanding of phase transformation and microstructure control in Pb-free solder joints.Advanced characterization techniques including synchrotron radiation provide a comprehensive toolset to measure the composition,crystallography,morphology,and properties of the major components of solder alloys.The research using such techniques is reviewed in detail including the characterization of the eff ects of microalloy additions on the microstructure and properties of Pb-free solder joints,especially those on the intermetallic phases.The discoveries outlined are of scientific and industrial relevance and have implications for new solder alloy composition design and the reliability of lead-free solder joints.

关键词： Cu_(6)Sn_(5)intermetallic Synchrotron radiation solidification Phase transformation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：