SUN Dongsheng LI Fengzhao Shandong Polytechnic University
,
Jinan
,
Laboratory of Atomic Imaging of Solids
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Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
ChinaDAI Jiyan LI Douxing Laboratory of Atomic Imaging of Solids
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
China associate professor
,
Institute of Materials Engineering
,
Shandong Polytechnic University
,
Jinan 250014
,
China
金属学报(英文版)
Observation under high resolution electron microscope shows that the continuous bombing of high speed ions produces a great amount of vacant site defects.The assembly of vacancies forms vacant dish,and the collapase of vacant dish forms stacking fault tetrahedrons and oth- er crystal defects.The interfaces between phase ε(Fe_(2-3)N)and phase γ'(Fe_4N)are smooth, straight and coherent,and they have the orientation relationships of(11)//(0001)and [110]/[110] .
关键词:
crystal defect
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null
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null
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GE Yunlong YANG Yuansheng JIAO Yuning HU Zhuangqi Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
ChinaGAO Yunyan JIA Guanglin Northeast University of Technology
,
Shenyang
,
China associate professor
,
Institute of Low Energy Nuclear Physics
,
Beijing Normal University
,
Beijing
,
100875
,
China
金属学报(英文版)
A new technique of centrifugal casting under electromagnetic field was firstly proposed and investigated.Taking a heat resisting alloy steel 25Cr20Ni and an Al-Cu alloy as examples,products,though their length,diameter and wall thickness are varied,re- vealed so superior macrostructures that the mechanical properties are much improved in comparison with conventional centrifugal casting.
关键词:
electromagnetic field
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null
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null
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JIANG Qichuan
,
YAN Jiulin
,
GUAN Qingfeng
,
WANG Shoushi
,
RONG Fujie
,
LI Zhang Jilin University of Technology
,
Changchun
,
China 130025
,
China associate professor
,
Jilin University of Technology
,
Changchun
金属学报(英文版)
By calculation of thermodynamics,analysis of crystal structure and study of TEM and eletron probe,it is first discovered that SiO2 can be acted as one of the heterogeneous nu- clei for lamellar intergorowth eutectic(austenite and cementite)crystallizing in modified as-cast medium manganese steel.
关键词:
SiO_2
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null
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null
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YANG Jilian ZHANC Baisheng DINC Yongfan China Institute of Atomic Engergy
,
Beijing
,
ChinaYANG Yingchang ZHANG Xiaodong Peking University
,
Beijing
,
ChinaPAN Shuming General Research Institute for Non-Ferrous Metals
,
Beijing
,
China associate professor
,
P.O.Box 275
,
Branch No.30
,
Beijing 102413
,
China
金属学报(英文版)
The N occupying sites and magnetic structures in R_2Fe_(17)N_x(R=Y,Dy,Nd)are de- termined by neutron diffraction.The effects of the site occupation of N on magnetic properties are discussed primarily.
关键词:
neutron diffraction
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null
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null
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null
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null
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XIAN Aiping LI Peiji CHEN Wenxiu WANG Yikang Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
ChinaCHEN Renvi MEI Dongsheng Panzhihua Institute of Iron and Steel Research
,
Ministry of Metallurgical Industry
,
Panzhihua
,
China associate professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The determination of dffusible hydrogen in U71Mn heavy rail steel,and hydrogen diffusivity as well as the hydrogen distribution in the cross section of blooms with stack cooling were stu- died.The results showed that,most of the hydrogen in blooms of heavv rail steel is diffusible, the hydrogen diffusivity in U71Mn rail steel blooms at room temperature is(0.85—1.02)× 10~(-6)cm~2/s,after stack cooling,the hydrogen content in bloom will decrease greatly which is helpful to form the flake-free phenomenon in the heavy rail produced by Panzhihua Iron and Steel Company.
关键词:
rail steel
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WANG Yanbin
,
WANG Anrong
,
CHU Wuyang
,
XIAO Jimei University of Science and Technology Beijing
,
Beijing
,
China associate professor
,
Department of Materials Physics
,
University of Science and Technology Beijing
,
Beijing 100083
,
China
金属学报(英文版)
The formation and aggravation of hydrogen damage in Fe-3 wt-% Si alloy during cathodic charging Were studied by means of Lange transmission X-ray topography.Results showed that hydrogen damage did not form in the specimens charged in 0.5 mol/L H_2S0_4 so- lution without poison,and occurred with addition of 250 mg/L As_2O_3 even at very low charge current density.As charging at a certain current density,the size of the damage may enlarge up to a limit yet no more by prolonged time.The damage size increased with increase of charging current density,but not so apparent at high current density. An external tensile stress could promote the formation of hydrogen damage obviously. It seems that for charging in H_2SO_4 solution containing poison,the drop of hydrogen permeation curve against time prolongation is due to the formation of hydrogen damages.
关键词:
hydrogen embrittlement
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null
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CHENC Zhaonian JIA Zhengming CHEN Nianyi Shanghai Institute of Metallurgy
,
Academia Sinica
,
Shanghai
,
China associate professor
,
Shanghai Institute of Metallurgy
,
Academia Sinica
,
Shanghai 200050
,
China
金属学报(英文版)
The NaF-CaF_2 system has been studied by molecular dynamics simulation.The pair correlation functions between cations and anions and the bond angle distributions of cation and anion triplets have been obtained.The bridging and complexing in the system are discussed based on the pair correlation functions and bond angle distributions.The results simulated show that the F~- ions around a Ca~(2+)ion do not form tetrahedron coordination,so some of small complexing clusters such as CaF_4~(2-)are hardly found.A possible structure of F~- ions around Ca~(2+)ions is that three Ca~(2+)ions constitute an equilateral triangle through three Ca-F-Ca bridges and two F~- ions are located over and under the center of the right triangle,respectively.Meanwhile,on the outside of the triangle,every Ca~(2+)ion has other two F~- ions as its neighbors.
关键词:
NaF-CaF_2 system
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null
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WANG Fuhui LOU Hanyi WU Weitao Corrosion Science Laboratory
,
Institute of Corrosion and Protection of Metals
,
Academia Sinica
,
Shenyang
,
China associate professor
,
Institute of Corrosion and Protection of Metals
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
Effect of a sputtered Co-30Cr-5Al microcrystalline coating on oxidation resistance of intermetallic compound TiAl and oxidation behavior of the bare TiAl were investigated at 900—1000℃ in static air.The oxidation kinetics for the TiAl alloy seems to approximately follow a linear rate law.Poor oxidation resistance of TiAl is due to the formation of the mixed Al_2O_3+TiO_2 scale which is loosely packed and easily spalled off.but not of dense and adherent pure Al_2O_3.A sputtered Co-30Cr-5Al coating,30 μm thickness,can remarkably improve the oxidation resistance of TiAl owing to the formation of adherent Al_2O_3 protective scale.However,many Kirkendall voids were formed between coating and substrate.
关键词:
CoCrAl microcrystalline coating
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null
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FU Changpu HAN Yong
,
L(?) Shuangyun AN Yunzheng Shaanxi Mechanical Engineering Institute
,
Xi'an
,
ChinaPAN Jingda DU Wenfeng Beijing Heavy Electric Machine Works
,
China associate professor
,
Department of Materials
,
Shaanxi Mechanical Engineering Institute
,
Xi'an 710048
,
China
金属学报(英文版)
Studies were made of the creep properties and structure change of steet 20Cr11MoVNbNB at 550-650℃.It is found that at 550℃ when creep stress>180 MPa there exists linear rela- tion with two different slopes β_1 and β-2 between transitional creep strain ε_β and creep time t~(1/3),and β_1(in initiol period)>β_2(in later period).The Creep rate of stable stage at 550℃ can be expressed by =Aσ exp(-Q_ /RT),where,n=4.7.A exp(-Q_ /RT)= 5.37×10~(-16).Apparent creep activation energy Q_ =430 kJ/mol at 550-650℃,which is much higher than the self-diffusion activation energy of atoms for matrix Fe.In creep process,as the creep stress and time increase,the total weight of precipitated phases and rela- tive weight of Cr,Mo and V increase,but those of Fe and Nb decrease in precipitated phases,
关键词:
20Cr11MoVNbNB
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null
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null
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null
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ZHANG Anfeng Xinjiang Engineering College
,
Urumqi
,
ChinaXING Jiandong LU Wenhua Xi'an Jiaotong University
,
Xi'an
,
China associate professor
,
Department of Mechanical Engineering
,
Xi'an Jiaotong University
,
Xi'an 710049
,
China
金属学报(英文版)
The oxidation behaviour of high Cr Cast iron was investigated at 950 and 800℃ in terms of Cr content in matrix and the amount of carbide.The morphology and types of oxide films and the microstructure of subsurface were also examined.The main conclusions are:1)The original chromium content in the matrix determines the type of oxide film and it is an important factor for the oxidation resistance of high chromium cast iron;2) The oxidation resistance improves with increasing carbide content at 950℃ because of the decomposition of the carbide,while the decompsition of the carbide do not take place at 800℃ so the oxidation resisteance do not improve with increasing carbide volume.
关键词:
high chromium cast iron
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null
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