M.Oda
,
K.Setoguchi
,
E.Fuchita and C.Hayashi(UFP Division
,
Vacuum Metallurgical Co.
,
Ltd.
,
516 Yokota
,
Sanbu-cho
,
Sanbu-gun
,
Chiba-pref.
,
Japan 289-12)
材料科学技术（英文）
UFPs are formed using gas evaporation methods. In the gas evaporation methods, configuration of UFPs are controlled to form chain-like shape, complex, and isolated UFP. UFP films can be formed through the gas deposition method, where formed UFPs are ejected out of a nozzle and deposited on a substrate, forming patterns
关键词:
Zheng FANG
,
Quanru ZHANG
,
Hengzhong ZHANG
,
Yuan FANG
材料科学技术（英文）
The thermoelectrochemistry (TEC), a novel cross discipline, is presented, including the basic equations for a cell and a half-cell reaction, the treatment of experimental data and its application to electro-generative leaching of mineral and to measuring thermodynamic and kinetic data of an electrode reaction. The TEC technology will play an important part in the research on the metallurgical process under various fields.
关键词:
Ming ZENG
,
Xinqiang YUAN
材料科学技术（英文）
Silica sol ceramic mold was made at room temperature with JN-30 silica sol, silica powder and NH4Cl. It is found that the harden time of silica sol ceramic mold is only 0.5 to 1.5 h under the amount of NH4Cl solution of 7% to 8% with 15% concentration, and less surface cracks occur by using vacuum drying. The proper vacuum drying process parameters: vacuum drying temperature is 80 to 100℃, drying time is 5 h and vacuum is 0.06 to 0.07 MPa. The harden mechanics, vacuum drying mechanics and the reason of less surface cracks of silica sol ceramic mold by vacuum drying were also analyzed in this paper.
关键词:
Silica sol
,
null
,
null
,
null
MU Lin
,
JIANG Xin
,
GAO Qiang-jian
,
WEI Guo
,
SHEN Feng-man
钢铁研究学报(英文版)
Abstract： Hydrogen-enrich iron making process is certainly to be an effective method to reduce greenhouse gases emission. However, the effect of hydrogen addition on the low temperature metallurgical property of sinter is still unclear. A detailed investigation was performed on the above topic. The results are as follows. When CO is partially replaced by H2, the RDI＜315 (RDI＜28) of sinter decreases with the increase of the H2 content; when the content of H2 increases, the CO, CO2 and N2 decrease proportionally, in this case, RDI＜315 (RDI＜28) of sinter increases with the increase of H2 content; the value of RDI＜315 (RDI＜28) basically depends on the reduction index (Ri).The experimental data of RDI＜28 based on Japanese industrial standard (JIS) are a little higher than the data of RDI＜315 based on Chinese industrial standard (CIS) in the same condition. In addition, for part of CO is replaced by H2: RDI＜28=338394+11585 RDI＜315; for other gases, except H2, are decreased proportionally: RDI＜28=1739678+042922 RDI＜315.
关键词:
Key words: sinter
,
hydrogen
,
reduction disintegration index (RDI)
,
metallurgical property
YUAN Zhangfu
,
YANG Xiao
,
LU Zhixing
,
HUANG Jiangning
,
PAN Yifang
,
MA Enxiang
钢铁研究学报(英文版)
A doubleparameter oxygen lance used in a 300 t converter was designed to improve the metallurgical performance. A smallscale measurement of the jet behavior was done using a computer controlled scanning system. The experimental data on the velocity distribution at the jet centerline, the contour map of the jet velocity, the deviation of the jet centerline, and the velocity distribution of the axial section were compiled. According to the results of the smallscale measurement, the doubleparameter lance was also employed for a BOF experiment. The metallurgy indexes show that the metallurgical performance was highly promoted by use of the doubleparameter lance.
关键词:
oxygen lance;jet behavior;BOF;metallurgical performance
Karin Gong
,
LUO He-li
,
ZHOU Zhi-feng
,
TIAN Zhi-ling
,
Lars Nyborg
,
LI Chang-hai
钢铁研究学报(英文版)
Iron alloyed Ni3Al with composition of Ni-18.8Al-10.7Fe-0.5Mn-0.5Ti-0.2B in atom percent (NAC alloy) showed attractive tribological properties under unlubrication condition at room temperature. The alloy was prepared by hot isostatic pressing (HIP) process. The wear properties were associated with its intrinsic deformation mechanism. Unfortunately, the single phase NAC-alloy worked inadequately with its counterpart disk, and also showed a poor machinability. In the present work, NAC-alloy matrix composite with 6% (volume percent) MnS particle addition was studied to improve its wear behaviors and performance on machining. Two metallurgical processes of HIP and vacuum casting were applied to produce the testing materials. Pin-on-disk (POD) measurements were carried out at room temperature. A commercial vermicular graphite cast iron was selected as a reference material. The counterpart disk was made of a grey cast iron as liner material in ship engines. The contact pressures of 2.83 MPa and 5.66 MPa were normally applied in the tests. The investigation indicated that MnS particle addition in the NAC-alloy composites functions as an effective solid lubricant, and improved wear properties and machinability of the materials. Obviously, as-cast NAC-alloy with in-situ formed MnS-phase was working more effectively with the counterpart, comparing to the HIPed NAC-alloy composite with MnS particles. At the high contact pressure of 5.66 MPa, the specific wear rate of the as-cast NAC-alloy composite was high. The phenomenon of the negative effect is mostly due to the brittle second NiAl phase as evidenced in the microstructure analysis.
关键词:
HIP processing
,
friction coefficient
,
specific wear rate
,
intermetallics
,
sliding wear
,
casting
,
machinability
Materials Science and Technology
The influence of carbon and aluminium on deoxidation during vacuum induction melting (VIM) of a Ni-6Cr2-Mo-6W -5Co alloy using a CaO crucible has been studied. It has been found that carbon plays a dominant role in deoxidation during the melting stage, and about 50-70%, of the initial oxygen can be removed. Thermodynamics calculations show that the C-O reaction is far from the equilibrium state, and experimental results for carbon and oxygen contents in the liquid alloy correspond with those when the CO partial pressure p(CO) is 10(3)-10(2) Pa. Aluminium addition can further reduce the oxygen content to below 6 ppm. Thermodynamics calculations for the C-Al, Al-CaO and C-Al2O3 reactions demonstrate that they can all take place during the melting process. These reactions bring about reductions in the amounts of carbon and aluminium, respectively, of about 1.3-3.5 times and 20-50 times those required for deoxidation only.
关键词:
Y.Q. Chang
材料科学技术（英文）
Co doped ZnO nanowires with different Co contents have been fabricated by a chemical vapor deposition method. X-ray diffraction results show that all the samples are of single phase and crystallize in wurtzite ZnO structure. The lattice parameter a increases with increasing Co content, while the parameter c has no obvious change with increasing Co. Raman spectra show that the nonpolar E2(High) mode becomes broad and weak with the doping of Co, which indicates that the incorporation of Co causes structural disorder in the crystalline columnar ZnO lattice. The photoluminescence spectra exhibit that the position of the ultraviolet emission shifts to short wavelength and the intensity decreases with increasing Co. The green emission is affected by
two contrary factors. It is increased by the introduced defects, but suppressed by the interaction between Co doping and native defects and the later affects it more significantly.
关键词:
Co doped ZnO nanowires
