W.Q. Zhang
,
Q.M. Liu
,
Y.F. Zhu
,
Y.S. Yang and Z.Q. Hu(State Key Laboratory of RSA
,
Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China)
金属学报(英文版)
An investigation on electromagnetically-stirred solidification of Al-CuAl2 eutectic system is presented in this paper. With electromagnetic stirring in solidification, structural transition from lamellar to rod-like eutectic has been found in the as-cast structures, and provided strong stirring is applied, proeutectic growth of α-Al phase is enhanced. Moreover, the interphase spacing of eutectic is clearly increased with melt flow intensified. Numerical computation of flow field is also presented, and the effect of stirring on structural formation is discussed.
关键词:
electromagnetic stirring
,
null
,
null
,
null
HU Hanqi Zheng Riqi University of Science and Technology Beijing
,
Beijing
,
China Dept.of Foundry
,
Faculty of Metallurgy
,
University of Science and Technology Beijing
,
Beijing 100083
,
China
金属学报(英文版)
The melt flow induced by the electromagnetic stirring in the molten low sulphur steel may re- fine the original austenite grains,but widen the secondary denritic arm spacings.As a result, the ultimate tensile strength of the steel will be improved and the reduction of area will be re- markably decreased.The microalloying by an addition of Ce may retard the unfavourable ef- fect of the electromagnetic stirring.
关键词:
electromagnetic stirring
,
null
,
null
Y. Zhang
金属学报(英文版)
The effects of electromagnetic stirring on the microstructures of pipe-line steel SAWdeposited metal were investigated. The results showed that electromagnetic stirringincreased the number density of inclusions with 0.2-0.6μm in diameter and promotedthe formation and refining of acicular ferrite within austenite grains. The low tem-perature toughness of deposited metal was improved.
关键词:
electromagnetic stirring
,
null
,
null
W.Q. Zhang
,
Y.F. Zhu
,
Y.S. Yang and Z.Q. Hu (State Key Lab. of RSA
,
Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China)
金属学报(英文版)
The effects of magnetic field on macro and microstructure of Al-CuAl2 eutectic alloy produced by electromagnetic centrifugal casting have been erperimentally investigated in the present paper. Electromagnetic stirring can lead to columnar formation in the cuter region and equiaxed in the inner, and otherwise cause the lamellae coarsened and the microstructure morphology to change from lamella to rod and then to block,if the electromagnetic stirring is intensified.
关键词:
electromagnetic stirring
,
null
,
null
Z.Q. Cao
,
L. Y Piao
,
X.G. Zhang
,
Z. Li and J.Z. jin(Research Center of Foundry Engineering
,
Dalian University of Technology
,
Dalian 116024
,
China)
金属学报(英文版)
It is found that the anomalous eutectics can be separated on macroscopic scale by flow caused by electromagnetic stirring, and the separated phase is the leading faceted phase with the solution entmpy over 23J/(mol.K). By using this technology, a new kind of composite pipe ond gear with good abrasive properties are made without adding any reinforced particles. Emphases are paid on the researehes about formation mechanism of seporated eutectic and abrasive property of the composite pipe or gear. The result shows that the entropy of solution controlling the eutectic microstructure is also valid and useful as a criterion of separated eutectic, and the kind and its chemical scope of the off-eutectic used to make composite can be calculated accoofing to this theory.
关键词:
composite pipe or gear
,
null
,
null
,
null
W.M. Mao
,
A.M. Zhao
,
X.Y. Zhong
金属学报(英文版)
The nondendritic semi-solid slurry preparation of high chromium cast iron Cr20Mo2
has been studied in this paper. The experiments show that the proeutectic austenitic
particles are more spherical under a larger stirring power condition, even if the stirring
time is shorter, while the proeutectic austenitic particles are not very much spherical
under a smaller stirring power condition and some proeutectic austenitic dendrites
also exist, even if the stirring time is very long. The experiments also show that when
stirred for 5{6 minutes under the test condition, the semi-solid slurry with 40vol.%{
50vol.% solid fraction and spherical proeutectic austenite in the size of 50{80¹m can
be obtained.
关键词:
high chromium cast iron
,
null
,
null
W.M. Mao
,
Z.S. Zhen
,
H.T. Chen
,
X.Y. Zhong
金属学报(英文版)
With the help of an electromagnetic stirring device and alloy melt quenching technology, the microstructure of semi-solid AZ91D magnesium alloy slurry stirred by a rotationally electromagnetic field was studied and the experimental results are shown as the following. The primary α-Mg grains are refined obviously when the slurry is stirred by a rotational electromagnetic field during continuously cooling and they are eventually changed to fine rosette grains or spherical grains. If the above semi-solid slurry is further stirred isothermally for some time, much more spherical primary α-Mg grains can be obtained. If the melt is first cooled down to a given semi-solid temperature and then starts being stirred by the rotational electromagnetic field, the primary α-Mg dendrites will be large, and a longer time will be taken and a larger stirring power will be needed for the secondary arms of the dendrites to be remelted on the roots to prepare an ideal semi-solid slurry. Theoretical analysis indicates that the strong flow motion leads to a more even temperature field and a solute field and stronger man-made temperature fluctuation in the AZ91D magnesium alloy melt so that the spherical primary α-Mg grains are increased in the slurry. Moreover, all the measures promoting the temperature fluctuation will be favorable to the formation of spherical primary α-Mg grains and all the factors increasing the arm's root remelting difficulty will be favorable to the formation of rosette-type primary α-Mg grains.
关键词:
AZ91D magnesium alloy
,
null
,
null
刘政
,
罗浩林
,
白光珠
中国稀土学报
doi:10.11785/S1000-4343.20150310
利用低过热度浇注和电磁搅拌技术制备半固态A356-Ce铝合金浆科.探讨了电磁搅拌频率对半固态初生α相形貌和Ce在凝固组织中的分布的影响.研究结果表明:在半固态A356-Ce合金浆料的制备过程中,电磁搅拌频率对半固态初生相的形貌以及Ce的分布影响很大,通过实验研究获得了制备半固态A356-Ce铝合金浆料的合适工艺参数,即在浇注温度为620℃,保温温度590℃,保温时间为10 min,稀土添加量为0.4％,搅拌时间为15s的条件下,搅拌频率为30 Hz的晶粒细化效果最佳,其平均形状因子为0.80,平均等级圆直径为76.1 μm,稀土分布也更均匀.
关键词:
半固态
,
电磁搅拌
,
初生α相
,
稀土分布
高小峰
连铸
铸坯低倍组织控制技术主要有：低恒温浇钢、电磁搅拌、结晶器钢水加入强生核剂及结晶器钢水降温。分析了铸坯低倍组织中心等轴晶的形成机制,探讨了铸坯低倍组织中心等轴晶的几种控制技术以及他们在生产中的应用情况,铸坯低倍组织控制技术的开发和实践应用,推动了铸坯低倍组织向优质化的进程,促进了连铸工业的迅速发展。
关键词:
中心等轴晶
,
生核剂
,
电磁搅拌
,
低温
,
结晶器
