WANG Yanan Anshan Institute of Iron and Steel Technology
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Anshan
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ChinaSONG Weixi University of Science and Technology Beijing
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Beijing
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China WANG Yanan
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Laboratory of Metallography
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Anshan Institute of Iron and Steel Technology
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Anshan
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Liaoning 114002
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China
金属学报(英文版)
An observation under TEM was carried out of the hetero-particles and stripes inside of the vermicular graphite in cast iron specimens which were prepared by isothermally quenching in ice-salt-water.The hetero-particles and stripes,composed of almost pure Fe and a little Si, were found in the regions of the growth direction changing of the vermicular graphite.Many twins and dislocations were also observed to contribute to changing the growth direction and to providing the growth steps of the graphite respectively.
关键词:
vermicular graphite
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null
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null
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null
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null
DU Linxiu
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ZHANG Zhongping
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TIAN Yuwei
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LIU Xianghua
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WANG Guodong
钢铁研究学报(英文版)
gy Center, Benxi Steel Group, Benxi 117000, Liaoning, China)
Abstract： The fatigue properties of 400 MPa grade supersteel, plain low carbon steel SS400 and microalloyed steel Q340TM were investigated through tensilecompression fatigue experiment with R=-1. The results indicate that the fatigue limit of the 400 MPa supersteel is higher than that of SS400 steel and close to that of the 340TM steel. According to the analysis of fatigue fracture, the fatigue striations of supersteel SS400 is thinner than that of SS400 steel and 340TM steel, and grain refinement can increase the fatigue limit.
关键词:
supersteel;grain refinement;fatigue property
Spectroscopy and Spectral Analysis
It is very important to detect trace elements for kilmberlite. Through improving the working conditions of X-ray fluorescence spectrometer and optimizing the analytical conditions, the determination method of trace elements, such as Sc, Cr, Ni, Y, Nb, La, in kimberlite was worked out. The method has been successfully applied to the determination of trace elements in over 2 thousand samples of kimberlite from Liaoning povince. The detection limits of the method were relatively low (the detection limit of Sc droped from 9.54 to 2.83 mug.g(-1) and the detection limit of La droped from 21.68 mug.g(-1) to 9.18 mug.g(-1)), i.e. 2.83, 2.15,2.20, 1.17,1.05 and 9.18 mug.g(-1) for Sc, Cr, Ni, Y, Nb and La, respectively. The precision of the method was very high with 2.10%-7.09% of RSD (n = 20). Compared with ICP spectrometry this method is satisfactory. The method has proven to be simple and rapid with low cost and high efficiency.
关键词:
kimberlite;X-ray fluorescence spectrometry;trace elements
YANG Zhongdong
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LIU Sulan
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LI Zhefu
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XUE Xiangxin
钢铁研究学报(英文版)
A new process of directly smelting boron steel from boroncontaining pig iron has been established. The starting material boroncontaining pig iron was obtained from ludwigite ore, which is very abundant in the eastern area of Liaoning Province of China. The experiment was performed in a mediumfrequency induction furnace, and Fe2O3 powder was used as the oxidizing agent. The effects of temperature, addition of Fe2O3, basicity, stirring, and composition of melt on the oxidation of silicon and boron were investigated respectively. The results showed that silicon and boron were oxidized simultaneously and their oxidation ratio exceeded 90% at 1 400 ℃. The favorable oxidation temperature of silicon was about 1 300-1 350 ℃. High oxygen potential of slag and strong stirring enhanced the oxidation of silicon and boron.
关键词:
boroncontaining pig iron;oxidation;silicon;boron
