检索结果-南通市图书馆

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

Effect of electromagnetic stirring on metallurgical quality of GCr15 electroslag ingot

在线全文

学校读者我要写书评

暂无评论

China Foundry 2022年第1期19卷 46-54页

作者： Xiao-fang Shi Tao Xu Li-zhong Chang School of Metallurgy Engineering Anhui University of TechnologyMa'anshan 243002AnhuiChina Anhui Fukai Special Material Co. Ltd.Jixi 245300AnhuiChina

To further improve the metallurgical quality of electroslag remelting,remove the large inclusions in electroslag ingot and refine the solidification structure of electroslag ingot,an electroslag remelting furnace with electromagnetic stirring was designed,and the influence of different magnetic induction intensities on metallurgical quality of GCr15 electroslag ingot was studied.Inclusions with different sizes and types were analyzed by an ASPEX scanning electron microscope,and the morphology and composition of inclusions were further observed by a JSM-6510LV scanning electron microscope.The distribution of alloying elements on the cross section of electroslag ingot was analyzed by original position analysis(OPA).The results show that whether or not electromagnetic stirring is used,the inclusions in electroslag ingot are mainly composed of Al_(2)O_(3),MnS,MnS-oxide and other oxides,among which Al_(2)O_(3) is the most.Compared with an electroslag ingot without electromagnetic stirring,the number of inclusions decreases considerably,and the proportion of small inclusions increases while the proportion of large inclusions decreases when the electromagnetic stirring with remelting current of 1.1 kA and magnetic induction intensity of 62 Gs is applied.However,excessive electromagnetic force will cause the number and diameter of inclusions to increase again.electromagnetic stirring has different effects on the segregation of different elements.Under the experimental conditions,the weak electromagnetic force with 1.1 kA and magnetic induction intensity of 108 Gs has little effect on the segregation of C,but decreases the segregation of P,and the excessive electromagnetic force aggravates the segregation of alloy elements.

关键词： electroslag remelting electromagnetic stirring inclusion solidification segregation GCr15 bearing steel

Effect of solidification mode on microstructure evolution and properties of magnesium alloy with long-period stacking ordered phase

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2024年第5期31卷 1127-1138页

作者： Hao Li Hong-mei Chen Xu Zhang Qian-hao Zang Jing Zhang Di Feng Yan-xin Qiao Yu-hang Guo School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang212100JiangsuChina School of Metallurgy and Materials Engineering Jiangsu University of Science and TechnologySuzhou215600JiangsuChina

The solidification methods of electromagnetic stirring(EMS)and non-electromagnetic stirring were employed to prepare Mg–6Gd–3Y–xZn–0.6Zr(x=1,1.5,2,3)alloys.The evolution of alloy microstructures and the changes in properties were analyzed for different Zn contents.It has been observed that in alloys without electromagnetic stirring,as the Zn content increases,the alloy structure gradually refines.The primary second phase transitions from Mg5RE phase to long-period stacking ordered(LPSO)phase,resulting in improved hardness and elongation.In alloys subjected to electromagnetic stirring,there is a relatively higher content of the second phase,primarily consisting of LPSO phase.After applying electromagnetic stirring,the quantity and the type of LPSO phase in the alloy change.The alloy structure becomes more uniform with electromagnetic stirring,resulting in increased hardness and reduced hardness gradients within the grains.The mechanical properties of alloys with electromagnetic stirring are superior to those without electromagnetic stirring.

关键词： Rare earth magnesium alloy LPSO phase electromagnetic stirring Casting Property

Microstructure of in situ Al_3Ti/6351Al composites fabricated with electromagnetic stirring and fluxes

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

Transactions of Nonferrous Metals Society of China 2010年第4期20卷 577-583页

作者：李桂荣王宏明赵玉涛陈登斌陈刚程晓农 Institute of Materials Science and Engineering Jiangsu University

The 6351 wrought aluminum alloy and K2TiF6-CaF2-LiCl components were selected as raw materials to fabricate in situ Al3Ti particulate reinforced aluminum alloy at 720℃via direct melt reaction method with electromagnetic stirring(EMS).CaF2 and LiCl acted as fluxes to lower the reaction temperature of the system.It is shown that the electromagnetic stirring and fluxes accelerate the emulsion process of K2TiF6.Optical microscopy,scanning electron microscopy,transmission electron microscopy and energy dispersive spectrum were utilized to analyze the microstructure and components of composites.Compared to composites fabricated without EMS and fluxes,the sizes of endogenetic Al3Ti are refined from 10-15μm to 2-4μm,which are often accompanied with silicon element.The morphology of Al3Ti or Al3TiSi0.22 exhibits triangle,quadrilateral and other clumpy patterns. Because of the Ca elements from CaF2,the sizes of Mg2Si decrease from 8-10μm to 1-2μm due to the formation of Ca2Si.

关键词： 6351 Al alloy microstructure in situ particle reinforced aluminum composites electromagnetic stirring fluxes

COMPUTER SIMULATION OF CONTINUOUS electromagnetic stirring FOR MAKING RHEOLOGIC SEMI-SOLID SLURRY OF ZL112Y ALUMINUM ALLOY

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2008年第6期21卷 108-114页

作者： LIU Changming YANG Ling ZUO Hongzhi College of Material Science and Engineering Chongqing University Chongqing 400044 China

To realize the technology of fabricating the rheologic semi-solid slurry of ZL112Y aluminum alloy via continues electromagnetic stirring process, ANSYS software was used to simulate electromagnetic force field and fluid velocity field in the alloy melt in a crucible tube in three coils. In the first section of the paper, eletromagnetic force field and fluid velocity field caused by single coil were simulated. The result of this simulation gives an average velocity of 3.2 cm/s and it is called critical velocity because a fluid velocity over it will cause a fine and spherical structure of solid primary a in a semi-solid melt. And, from this result, a reasonable temperature of semi-solid of the alloy and an electrical current intensity were established. The electrical current intensity of the result of this simulation corresponded to the current intensity used in a practice experiment, in which the primary α was obviously refined and sphericized. Based on this simulation of single coil electromagnetic stirring, in the second section of the paper, eletromagnetic force field and fluid velocity field caused by three coils were simulated. The result of the simulation shows that, 1） there is a semi-solid zone of 32 mm from bottom of the crucible tube to the upper; 2） the electrical current intensities of three coils of 400 A, 600 A, and 400 A, which were set to top range, middle range and bottom range of the tube, respectively, were the optimum parameters of electromagnetic current intensity under the condition of this investigation; and 3） under effect of these electromagnetic current intensity, the fluid velocities of the melt in the tube were 6.3 cm/s in top range, 3.75 cm/s in middle range, and 3.9 cm/s in bottom range of it, respectively.

关键词： electromagnetic stirring electromagnetic force field Fluid velocity field Rheologic semi-solid slurry Computer simulation

Preparation of CuCr alloys by thermit-reduction electromagnetic stirring

在线全文

学校读者我要写书评

暂无评论

Journal of University of Science and Technology Beijing 2007年第6期14卷 538-542页

作者： Zhihe Dou Tingan Zhang Haien Yu Liping Niu Xiaoli Jiang Huan Yang School of Materials and Metallurgy Northeastern University Shenyang 110004 China

The influences of the additive CaF2, different molds, mold pre-heating temperature, electromagnetic stirring, and alloying elements on CuCr have been investigated respectively during the preparation of CuCr alloys by thermit-reduction electromagnetic stirring. The results indicate that the reasonable reactant mass ratio of CuO： Cr2O3：Al is 100：140：160; CaF2 can reduce the solidification point of slags to improve the metal separating efficiency from slags; the crystal particles become thinner because of the high cooling velocity in the metal mold; while casting in the graphite mold, the casting properties of CuCr improve with the increase of pre-heating temperature; the compact alloys are prepared at 500℃; electromagnetic stirring can prevent the growth of dendrite crystal into refine crystal particles, as well as homogenize Cu and Cr to improve the CuCr properties; the optimal stirring time is 7 min; when the alloying elements Ni and Co are added to the reactants, elements Cu and Cr can distribute evenly but the crystal particles become thick.

关键词： contact material CuCr alloy thermit reduction electromagnetic stirring additive

Analysis of cracking phenomena in continuous casting of 1Cr13 stainless steel billets with final electromagnetic stirring

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2016年第5期23卷 534-541页

作者： Yu Xu Rong-jun Xu Zheng-jie Fan Cheng-bin Li An-yuan Deng En-gang Wang Key Laboratory of electromagnetic Processing of Materials (Ministry of Education) Northeastern University Research Institute Baoshan Iron & Steel Co. Ltd.

Solidification cracking that occurs during continuous casting of 1Cr13 stainless steel was investigated with and without final elec- tromagnetic stirring （F-EMS）. The results show that cracks initiates and propagates along the grain boundaries where the elements of carbon and sulfur are enriched. The final stirrer should be appropriately placed at a location that is 7.5 m away from the meniscus, and the appropri- ate thickness of the liquid core in the stirring zone is 50 ram. As a stirring current of 250 A is imposed, it can promote colurnnar-equiaxed transition, decrease the secondary dendrite arm spacing, and reduce the segregation of both carbon and sulfur. F-EMS can effectively de- crease the amount of cracks in 1Cr13 stainless steel.

关键词： stainless steel cracking solidification continuous casting electromagnetic stirring

Distribution of SiC_p in Al and Al-Cu Alloy Centrifugally Cast with electromagnetic stirring

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2004年第4期20卷 448-450页

作者： WeiqiangZHANG HaifangSHI HuamengFU DepartmentofMaterialsScienceandEngineering Liaoning~rechnicalUniversity47ZhonghuaRoadFuxin123000China InstituteofMetalResearch ChineseAcademyofSciencesShenyang110016China

The SiCp/(AI-Cu) alloy and pure Al matrix composites have been prepared by the centrifugal casting with electromagnetic stirring. There are two particle-depleted zones formed in the samples without electromagnetic stirring. electromagnetic stirring may result in a homogeneous distribution of fine SiC particles in the AI-Cu alloy, whereas it has little effect on the segregation in pure Al matrix. The results also show that the particle segregation is influenced by particle size and the coarse particles are more readily segregated than the fine ones.

关键词： Centrifugal casting Particle distribution electromagnetic stirring Solidification

Effect of electromagnetic stirring on the microstructure and wear behavior of iron-based composite coatings

在线全文

学校读者我要写书评

暂无评论

Journal of University of Science and Technology Beijing 2008年第4期15卷 451-456页

作者： Jiangbo Cheng Binshi Xu Xiubing Liang Yixiong Wu Zhengjun Liu School of Materials Science and Engineering Shanghai Jiaotong University Shanghai 200240 China National Key Laboratory for Remanufacturing Academy of Armored Force Engineering Beijing 100072 China School of Materials Science and Engineering Shenyang University of Technology Shenyang 110023 China

The effect of electromagnetic stirring on the microstructure and wear behavior of coatings has been investigated. A series of iron-based coatings were fabricated by the plasma-transferred arc cladding process by applying different magnetic field currents. The microstructure and wear resistance of the composite coatings were characterized by scanning electron microscope （SEM）, en- ergy dispersive X-ray analysis （EDAX）, X-ray diffraction （XRD）, and wet sand rubber wheel abrasion tester. The experimental results showed that the microstructure of the coatings was mainly the γ-Fe matrix and （Cr, Fe）7C3 carbide reinforced phase. The coatings were metallurgically bonded to the substrate. With increasing magnetic field current, the amount of the block-like （Cr, Fe）TC3 carbide reinforced phase increased at first, reached a local maximum, and then decreased sharply. When the magnetic field current reached 3 A, the block-like （Cr, Fe）TC3 carbides with high volume fraction were uniformly distributed in the matrix and the coating displayed a high microhardness and an excellent wear resistance under the wear test condition.

关键词： composite coatings plasma transferred arc cladding electromagnetic stirring microstructure wear resistance

Grain Size Control of Semisolid A356 Alloy Manufactured by electromagnetic stirring

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2005年第2期21卷 219-225页

作者： P.K.Seo C.G.Kang National Research Lab of Thixo-Rheo FormingSchool of Mechanical Engineering Pusan National University Pusan 609-735 KoreaNational Research Lab of Thixo-Rheo FormingSchool of Mechanical Engineering Pusan National University Pusan 609-735 Korea

To investigate the possibility of substituting the mechanical stirring system with electromagnetic stirring (EMS) system for aluminum rheo die-casting, the EMS under the different stirring cooling conditions was carried out. It was found that in the early period of solidification, the dendrite breakages led to a fine primary phase. When dendrites grew coarsely, the effect of ripening on grain size overwhelmed that of dendrite breakage. It was also found that the high cooling rate favored large nucleation rate, and led to a fine primary phase. But high cooling rate also made the growth rate of the dendrite arm, which prevented the dendrite arm from being sheared off. Therefore there were a suitable stirring time and suitable cooling rate to obtain the best rheo die-casting structure. Qualified semisolid A356 aluminum alloy was successfully manufactured with short time EMS.

关键词： Semisolid metal process electromagnetic stirring Rheo die-casting Grain size control