S.S. Xie
,
X.F. Pan
,
T.L. Wang
,
Z.X. Wang
,
H.C. Yang and Q. Wang ( School of Materials and Metallurgy
,
Northeastern Universityl Shenyang 110006
,
China)( School of Materials and Metallurgy
,
Northeastern Universityl Shenyang 110006
,
China)( School of Materials and Metallurgy
,
Northeastern Universityl Shenyang 110006
,
China)( School of Materials and Metallurgy
,
Northeastern Universityl Shenyang 110006
,
China)( Institute of Metal Research
,
The Chinese Academy of Science
,
Shenyang 110015
,
China)( Liaoning Machinery Industry Foreign Trade Co. Ltd.
,
Shenyang 110002
,
China)
金属学报(英文版)
Threshold stress values, muging from ～8 to 16MPa·m1/2 can be obtained in a Ni-base alloy GH586 by varying the microstructure through heat treatments. The threshold and low crack growth rate behaviors at room temperature, with varying groin size and γ'-distribution, have been investigated. The results indicate that grain size is an important microstructurol parameter that affects fatigue crack growth threshold and propagation behaviors, as the values of △Kth increase with increasing grain size, but the γ' -distribution also has important effect. Analyses show that the effects of groin size on threshold and low crack-growth rate behavior result from heterogeneous deformation and roughness-induced crack closure due to crystallographic slipping and cracking in coarse microstructure. The higher △Kth and lower fatigue crack growth rate with increasing amounts of fine γ' phases are closely related to less damage accumulation level in deformation zone of crack-tip resulted from heterogeneous deformation due to dislocations' shearing γ' precipitates.
关键词:
superalloy GH586; fatigue crack growth; threshold; grain size;γ'-distribution
SUN Wenqiang
,
CAI Jiuju
,
MAO Hujun
,
GUAN Duojiao
钢铁研究学报(英文版)
As the largest energy consuming manufacturing sector and one of the most important sources of carbon dioxide (CO2) emissions, the China′s iron and steel industry has paid attention to the study of changing trend and influencing factors of CO2 emissions from energy use. The logarithmic mean Divisia index (LMDI) technique is used to decompose total change in CO2 emissions into four factors: emission factor effect, energy structure effect, energy consumption effect, and steel production effect. The results show that the steel production effect is the major factor which is responsible for the rise in CO2 emissions; whereas the energy consumption effect contributes most to the reduction in CO2 emissions. And the emission factor effect makes a weak negative contribution to the increase of CO2 emissions. To find out the detailed relationship between change in energy consumption or steel production and change in CO2 emissions, the correlation equations are also proposed.
关键词:
CO2 emissions
,
energy use
,
LMDI technique
,
steel production
,
energy consumption
Yang LUO
材料科学技术（英）
Due to continued growth in key markets, a broadening of application base and performance improvements, the market demands of NdFeB magnet increased steadily in 1998, and the global output of sintered NdFeB magnet exceeded 10,000 t, in spite of the economic recession in Asia. In 1998 China produced 3,850 t sintered NdFeB block magnet, with an annual growth rate of +22% over the output in 1997.
关键词:
HU Changqing
,
CHEN Liyun
,
ZHANG Chunxia
,
QI Yuanhong
,
YIN Ruiyu
钢铁研究学报(英文版)
The sustainable development against global warming is a challenge faced by societies at global level. For steel industry, the pressure of reducing CO2 emission is likely to last many years. During the past decades, the CO2 emission per ton steel has been reduced mainly due to the improvement of energy efficiency. Entering the 21st century, the steel manufacturing route must have three functions, namely, production of high performance steel products, conversion of energy, and treatment of waste. In the near future, it is expected that existing BFBOF and EAF routes will be improved, in order to produce high performance steels, increase the use of scrap, and integrate steel industry with other industries for mitigating CO2 emission. In the long term, using carbonfree energy, reducing agents, and storing CO2 securely or converting CO2 into a harmless substance can be presumed for tremendous reduction in CO2 emission.
关键词:
global warming;CO2 emission;steel industry;emission mitigation
新型炭材料
The nano-sized quasi-one-dimensional hollow cores of carbon nanotubes make it possible for them to be filled with foreign substances. The physical and chemical properties of the filled carbon nanotubes are closely related to the type., the structure and the composition of the filling materials. Therefore, it is expected that various types of filled-carbon nanotubes can be designed and assembled to meet the application demand. This article reviews the current status of research in this area. Various chemical and physical methods and the possible mechanisms of filling the carbon nanotubes with foreign substances as well as that of encapsulating foreign substances during the preparation process are presented. The promising applications of nanotubes filled with foreign substances in the fields of electronics, information technology, biochemistry and medicine etc., are introduced. Furthermore, some necessary studies in the future, such as the mechanism of the interaction of the carbon nanotubes and the filling substances, the physical properties of the quantum lines and the preparation technique of aligned and filled carbon nanotubes are proposed.
关键词:
carbon nanotubes;encapsulation;filling;catalytic pyrolysis;large-scale;metal nanowires;thin-films;single;encapsulation;nanoparticles;capillarity;crystals;nickel
