TANG Guoyi ZHENG Yangzeng Yanshan University
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Qinhuangdao
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ChinaCAI Qigong
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ZHU Jing Central Iron and Steel Research Institute
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Ministry of Metallurgical Industry
,
Beijing
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China TANG Guoyi
,
Dept.of Graduates
,
Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing 100081
,
China
金属学报(英文版)
The effects of chemical composition and cooling rate after solidication on the grain coarsening temperature,T_(GC),of the V-Ti-N microalloyed steels have been investigated.It is shown that the T_(GC) may be obviously raised by adding even a little Ti to the base steel so as to pre- cipitate a great deal of fine Ti-bearing particles of about 10 nm.The T_(GC) does not increase with the cooling rate,as it is over a certain critical value.The T_(GC) is insensitive to any varia- tion of N content at simulated cooling condition of 150 mm continuous cast slab.The T_(GC) may be dropped down about 100℃ by adding 0.33 wt-%Mo to the steels.The sensitivi- ty of T_(GC) to cooling condition relates to the Ti and V contents.
关键词:
microalloyed steel
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null
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Zengqi ZHAO Lab.of Physics
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Baotou Research Institute of Rare Earth
,
Baotou
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014010
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ChinaFeixia CHEN Dazhi YANG Dept.of Mater.Eng.
,
Dalian University of Technology
,
Dalian
,
116024
,
ChinaEr BAO Dept.of Mater.Eng.
,
Yanshan University
,
Qinhuangdao
,
066004
,
China
材料科学技术（英文）
Isothermal aging behaviours of a CuZnAl shape memory alloy have been investigated by means of dilatometry.The length of the specimens during isothermal aging from 190 to 280℃ increases with the aging time at each temperature.The isothermal aging kinetics fits in Avrami equation and the time exponent n decreases with the increase in aging temperature.The apparent activation energy for the isothermal aging process was measured to be 109.0kJ/mol,which is about equal to that of a relaxation internal friction peak at about 200℃ (f≈1 Hz) in the alloy.
关键词:
isothermal aging kinetics
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TANG Guoyi ZHENG Yangzeng Yanshan University
,
Qinhuangdao
,
ChinaCAI Qigong ZHU Jing Central Iron and Steel Research Institute
,
Beijing
,
China ZHENG Yangzeng Professor
,
Department of Material Engineering
,
Yanshan University
,
Qinhuangdao
,
China
金属学报(英文版)
The characteristics and the formation of the miscible particles in V-Ti-N microalloyed steels were studied.It was found that the vanadium to form V-Ti miscible particles starts to precipi- tate after pouring and cooling to temperature below 11 50℃ by means of the epitaxial precipi- tation on the pre-existing titanium nitrides.The vanadium content in the particles is markedly influenced by the cooling rate after solidification.
关键词:
microalloyed steel
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null
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LIN Chengfu WEN Lishi QIAN Shengwei Institute of Metal Research
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Academia Sinica
,
Shenyang
,
ChinaKANG Datao Yanshan University
,
Qinhuangdao
,
China LIN Chengfu
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The morphology,microstructure,chemical composition and electrochemical behavior of the flame sprayed Zn-Al15 coating after corrosion test in sea water have been investigated.The results show that the selective dissolution of the laminar euteetic structure of the Zn-AI15 coating is the fundamental cause for its similarity in electrochemical behavior with Zn coating and kinetic behavior with Al coating.In the beginning period of sea water corrosion,the com- bined action of the laminar eutectic structure of the coating together with the residual stress may induce the stress corrosion cracking of the coating,and result in the crevice corrosion. The coating then will bulge and.fail in local areas due to embrittlement itself,stacking and ex- pansion of corroded products under the residual stress.
关键词:
flame sprayed coating
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LI Dongchun TIAN Yongjun CHEN Shizhen YU Dongli HE Julong ** Yanshan University
,
Qinhuangdao
,
066004
,
China+ To whom correspondence should be addressed
材料科学技术（英文）
Nickel,as the carrier through which Fe atoms diffuse,obviously enhances the densification of sintered compact containing short cast iron fibre. When Ni content is above 4.5 wt-% there are some austenites in microstructure at room temperature, discontinuous cementite networks at the interfaces between austenites and pearlites,free graphite pre- cipitated in austenite and pores and Widmannst(?)tten carbide precipitated in austenite. When Ni content is about 12 wt-%,it leads to de- crease in densification ratio and change in fracture morphology of sintered compact from ductile to brittle.
关键词:
short metal fibre
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null
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ZHENG Yangzeng ZHANG Fucheng Yanshan University
,
Qinhuangdao
,
China
金属学报(英文版)
The heterogeneous distribution of C and metallic alloying elements as well as the phase com- position changes before and after cold deformation of an Fe-Mn-Cr-C alloy have been stu- died by the use of Mssbauer spectroscopy.The austenites without and with C and metallic alloying elements are found in the alloy in as-solid solution state.While the martensites with- out and with C and alloying elements may be induced by cold deformation.The transforma- tion from austenite to martensite in the alloy is confirmed via theoretical computation and ex- periments to be controlled by the number of covalent electron pairs forming covalent bond in austenitic crystal cell of the alloy.The formation of strong covalent bond between C and me- tallic elements can vigorously retard the γ/α' transformation.
关键词:
heterogeneity
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