J. Zhang1
,
2)
,
G.P. Li1) and D. Li1) 1) Institute of Metal Research
,
The Chinese Academy of Sciences
,
Shenyang 110015
,
China 2) Shenyang University
,
Shenyang 110044
,
China
金属学报(英文版)
omesolution treatmentsfor Ti 5 8 Al 4 8Sn 2 0Zr 1 0 Mo 0 34Si 0 90 Nd (1 # alloy) , Ti 6 3 Al 4 8 Sn 2 0 Zr 1 0 Mo 0 34 Si 0 90 Nd(2 # alloy) and Ti 6 8 Al 4 8Sn 2 0 Zr 0 5 Mo 0 34 Si 0 70 Nb 0 90 Nd (3 # alloy) several near alpha Titanium alloysat various temperaturesin (α+ β) two phaseregion havebeen carriedout. Theeffectsofsolution treat menttemperatureon theshape,size, distribution andvolumefraction ofthe primary alpha phase(αprim)havebeeninvestigated. Theresultsshowed thattheshape ofαprim did not depend onthesolution temperature, butthesize, the distribution and the volume fraction changed withthevariedsolutiontreatmenttemperature. Theprimaryalpha phaseprincipally precip itated atthe βgrain boundary regions atthe higher temperature nearthe Tα+ β/ β, and asthe temperature was dropped, αprim precipitated in a more uniform way. By energy spectrumanalysisof SEM, the elemental distributionsin primary αphase and transformed βphase(βtrans) havebeeninvestigated. The resultsshowed thatthe amount of Alelementin αprim is higherobviouslythanin βtransathighertemperature. Asthesolution temperature gotdropped theconcentrationsof aluminum elementgot moreuniform in both αprim and βtrans. Thehigher concentration of aluminum elementin αprim would play a importantrolein orderedα2 phase precipitation, and so have an importanteffecton the high temperature properties of the al loys.
关键词:
titanium alloy
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null
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null
Chinese Science Bulletin
A study was carried out in order to investigate the effect of contaminants and meteorological variables on the rust layer of carbon steel exposed in Shenyang urban atmosphere. Seven kinds of contaminants and twelve kinds of meteorological parameters were also registered in order to correlate the data with respect to corrosion rate and the stepwise multiple regression analysis was carried out in order to obtain the best regression model. The sum of rainfall time as well as sunshine time and the concentration of H(2)S could stimulate initial atmospheric corrosion of carbon steel. The initial atmospheric corrosion kinetics of carbon steel was observed to follow the cubic equation. The corrosion products were analyzed by XRD and the transformation of phases in different periods was discussed.
关键词:
contaminants;meteorological parameters;carbon steel;urban atmospheric;corrosion;stepwise multiple regression;corrosion products;rust;pollution
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
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energy use
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LMDI technique
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steel production
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energy consumption
American Mineralogist
A natural high-pressure phase of titanium oxide with alpha-PbO2-structure has been found in omphacite from coesite-bearing eclogite at Shima in the Dabie Mountains, China. High-resolution transmission electron microscope observations have revealed an orthorhombic lattice, corresponding to alpha-PbO2-type TiO2, with cell parameters a = 0.461 nm, b = 0.540 nm, c = 0.497 nm and space group Pbcn. It occurs as nanometer-thick (< 2 nm) lamellae between multiple twinned rutile crystals, providing additional evidence of very high-pressure, metamorphism at 7 GPa, 900 degrees C. This implies subduction of continental material to a depth of more than 200 kilometers. alpha-PbO-type TiO2 could be an extremely useful index mineral for ultrahigh-pressure.
关键词:
high-pressure phase;ries crater;rutile;polymorph;titanium
QIAO Lijie LIU Rui XIAO Jimei University of Science and Technology Beijing
,
Beijing
,
China
金属学报(英文版)
The effects of stress components on nucleation sites and propagation directions of stress cor- rosion cracks in brass were investigated with specimens under mode Ⅱ and mode Ⅲ loadings. The results indicated that under mode Ⅱ loading,stress corrosion cracks nucleated on the site with maximum normal stress component and propagated along the plane perpendieular to the maximum normal stress,under mode Ⅲ loading,the stress corrosion crack was not evident on the 45°plane due to the general corrosion in aqueous solution with high NH_4OH concentra- tion,while stress corroded in aqueous solution with low NH_4OH concentration, numerous cracks with spacings of 10—150μm were found on the 45°plane with maximum normal stress and no stress corrosion cracks was observed on the plane with maximum shear stress.
关键词:
stress corrosion cracking
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null
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null
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null
LIANG Yong LI Ruiguo Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
ChinaInstitute of Corrosion and Protection of Metals
,
Aademia Sinica
,
Shenyang
,
110015
,
China
材料科学技术（英文）
Recent advances in laser coating technology including laser cladding,laser surface alloying and laser vapour deposition in China are reviewed in this paper.
关键词:
laser
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null
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null
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null
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null
American Mineralogist
Our efforts to introduce defects in rutile by conventional mechanical grinding as used for TEM study did not produce any defects or twinning. Experimental SAED patterns of rutile with intercalated alpha-PbO2-type TiO2 lamellae are consistent with those expected from calculated patterns. The values and precision of lattice parameters of alpha-PbO2-type TiO2 derived from such SAED patterns are also consistent with crystal data from X-ray diffraction studies.
关键词:
TiO2;high-resolution transmission electron microscope;Dabie Mountains;UHP metamorphism
