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Baosteel Technical Research 2019年第4期13卷 20-29页

作者： HE Yutian XU Changzheng Research Institute Baoshan Iron & Steel Co.Ltd.

In this study,the solidified microstructure and segregation behaviors of the alloying elements and precipitate behaviors of the UNS N10276 alloy in a large-scale electroslag remelting(ESR)ingot were ***,the formation of the solidified microstructure and segregation of ESR were systematically analyzed via thermodynamic *** ESR ingot of the UNS N10276 alloy exhibits a typical dendritic *** secondary dendrite spacing at the head of the ingot is clearly larger than that at the bottom of the *** alloying elements(e.g.,Mo,Mn,Si,and C),which are positive segregation elements,segregate to the interdendritic zones during the solidification ***,Fe,W,and Cr segregate to the dendritic trunk zones,indicating that they are negative segregation *** the alloying elements,Mo segregates the most,especially at the head of the ESR *** of the precipitates that precipitate in the interdendritic zones and at grain boundaries belong to large-scale μ and M6C phases,*** is the main element of the *** precipitates at the head of the ESR ingot are more abundant and larger than those at the bottom of the ***,to improve the metallurgical quality and hot working properties of the UNS N10276 alloy,the segregation of the Mo element should be minimized,whereas the formation of the precipitates should be reduced as much as possible during the optimization of the composition and production processes.

关键词： alloy UNS N10276 solidified microstructure segregation precipitates thermodynamic calculation

microstructure and compression deformation behavior in the quasicrystalreinforced Mg-8Zn-1Y alloy solidified under super-high pressure

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Journal of Rare Earths 2014年第11期32卷 1048-1055页

作者：董允林小娉徐瑞郑润国樊志斌刘士俊王哲 School of Materials and Metallurgy Northeast University State Key Laboratory of Metastable Materials Science & Technology Yanshan University

The microstructure of Mg-8Zn-1Y alloy solidified under super-high pressure was analyzed through X-ray diffraction（XRD）, scanning electron microscopy（SEM） and energy dispersive spectroscopy（EDS）. And, compression deformation behavior at room-temperature was studied. The results showed that the microstructure of Mg-8Zn-1Y alloy solidified under ambient pressure and super-high pressure was both mainly composed of ■-Mg and quasicrystal I-Mg3Zn6 Y. Solidification under super-high pressure contributed to refining solidified microstructure and changing morphology of the intergranular second phase. The morphology of intergranular second phase（quasicrystal I-Mg3Zn6Y） was transformed from continuous network（ambient pressure） to long island（high pressure） and finally to granular（super-high pressure） with the increase in pressure. The compressive strength, yield strength and rupture strain of the samples solidified under ambient pressure were significantly improved from 262.6 MPa, 244.4 MPa and 13.3% to 437.3 MPa, 368.9 MPa and 24.7% under the pressure of 6 GPa, respectively. Under ambient pressure, cleavage plane on compressive fracture was large and smooth. When it was solidified under the pressure ranging from 4 to 6 GPa, cleavage plane on compressive fracture was small and coarse. In addition, dimple, tear ridge and lobate patterns existed.

关键词： Mg-8Zn-1Y alloy super-high solidification solidified microstructure room-temperature compression deformation compressive property rare earths

microstructure refinement of AZ31 alloy solidified with pulsed magnetic field

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Transactions of Nonferrous Metals Society of China 2010年第9期20卷 1685-1690页

作者：汪彬杨院生孙明礼 College of Engineering Zhejiang Normal University Institute of Metal Research Chinese Acad emy of Sciences

The effects of a pulsed magnetic field on the solidified microstructure of an AZ31 magnesium alloy were *** experimental results show that the remarkable microstructural refinement is achieved when the pulsed magnetic field is applied to the solidification of the AZ31 *** average grain size of the as-cast microstructure of the AZ31 alloy is refined to 107 μ*** quenching the AZ31 alloy, the different primary α-Mg microstructures are preserved during the course of *** microstructure evolution reveals that the primary α-Mg generates and grows in globular shape with pulsed magnetic field, contrast with the dendritic shape without pulsed magnetic *** pulsed magnetic field causes melt convection during solidification, which makes the temperature of the whole melt homogenized, and produces an undercooling zone in front of the liquid/solid interface, which makes the nucleation rate increased and big dendrites *** addition, the Joule heat effect induced in the melt also strengthens the grain refinement effect and spheroidization of dendrite arms.

关键词： AZ31 magnesium alloy grain refinement pulsed magnetic field solidified microstructure

microstructure Refinement of Mg-Gd-Y-Zr Alloy Under Pulsed Magnetic Field

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Journal of Iron and Steel Research International 2012年第S1期19卷 446-450页

作者： WANG Bin YANG Yuan-sheng College of Engineering Zhejiang Normal University Institute of Metal Research Chinese Academy of Sciences

The effects of pulsed magnetic field on the solidified microstructure of Mg-Gd-Y-Zr alloy were investigated. Fine uniform equiaxed grains are acquired in the whole ingot by the pulsed magnetic field treatment,and the average grain size of the as-cast φ50 mm and φ100 mm ingots is refined to 37 μm and 47 μm with the pulsed magnetic *** macrosegregation of solute elements of Mg-Gd-Y-Zr alloy is also reduced by the pulsed magnetic field treatment. Structure refinement is due to the electromagnetic undercooling zone in front of the solid/liquid interface by the magnetic pressure,and reduction of temperature gradient by the vibration of melt resulted from the pulsed magnetic field,which increases the nucleation rate and prohibits dendrite *** addition,primary α-Mg dendrites break into fine crystals, resulting in a refined solidification structure of the magnesium *** Joule heat effect induced in the melt also strengthens the grain refinement effect and the spheroidization of dendrite arms.

关键词： pulsed magnetic field solidified microstructure grain refinement Mg-Gd-Y-Zr alloy