PAN Chunxu SHI Yuxiang WANG Renhui GUI Jianian Wuhan University
,
Wuhan
,
China Wuhan University of Water Transportation Engineering
,
Wuhan
,
China Professor
,
Department of Physics
,
Wuhan University
,
Wuhan
,
China
金属学报(英文版)
The successive alteration o the microstructure from the weld metal zone through weld bond to the heat affected zone of a Cr18Ni13 austenitic-0.45%C steels weld joint was observed in situ using transmission electron microscopy.It was found a new type of microstructure called pearlite-like structure and observed the characteristics of the boundary of dissimilar phases. Based on the definition of various zones of the dissimilar steels weld joint under the optical mi- croscope,the transmission electron microscopic characteristics,including microstructures and compositions,of each zone are described and discussed.
关键词:
weld joint microstructure
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null
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LIU Zaihua Huazhong University of Science and Technology
,
Wuhan
,
China ZHAO Dongli Bureau of Complete Sets of Equipment
,
State Machinery Commission
,
Beijing
,
China Dept.of Mechanics
,
Huazhong University of Science and Technology
,
Yujiashan
,
Wuhan
,
China
金属学报(英文版)
The size effect of tension round bars with circumferential crack was described and used to measure the plane-strain fracture toughness K_(1c) of median or low strength steel.The size of cylindrical specimen required for K_(1c) measurement is much smaller than that of standard specimen.The J-integral values of the cylindrical sqecimens were calculated to characterize the size effect.The finite element calculution and fracture morphology analysis have been conducted to eyplain the fact that smaller cylindrical specimen could be used to measure K_(1c) of median or low strength steel.
关键词:
median or low strength steel
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null
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ZO U Hongcheng DAI Shujuan QIAN Zhixiong LI Guangxia Huazhong University of Science and Technology
,
Wuhan
,
China [Originally published in ACTA METALL SIN(CHINESE EDN)25(3)1989 pp A207—A212
,
Associate Professor
,
Division of Materials
,
Huazhong University of Science and Technology
,
Wuhan
,
China
金属学报(英文版)
The change of microstructure of fatigue specimens before and after laser radiation was studied by transmission electron microscopy.The results show that the diameter of dislocation cell λ tends to a constant at fatigue failure.Based on the principles of continuous damage mechanics,expressions of the fatigue damage criterion and processes of fatigue damage evolu- tion for L Y12CZ have been derived.
关键词:
laser radiation
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null
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null
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RAO Jianxi Naval Academy of Engineering
,
Wuhan
,
China MA Ruzhang University of Science and Technology Beijing
,
Beijing
,
China HE Yusheng Tsinghua University
,
Beijing
,
China MA Ruzhang Professor
,
Department of Metal Physics
,
University of Science and Technology Beijing 100083
,
Beijing
,
China
金属学报(英文版)
Measurements by using the ultrasonic technique together for electric resistance verified that the first sound velocity valley on cooling is mainly due to the soft-mode of driving the com- mensurate phase transition,and the second one due to the soft-mode of driving the martensitic transformation.The starting point,R_s,and finishing point,R_f,of the commensurate phase transition of the alloy have been determined.
关键词:
incommensurate phase transition
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null
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ZHAO Jiarong YANG Jie Wuhan Iron and Steel University
,
Wuhan
,
China ZHAO Jiarong
,
associate professor
,
Faculty of Rolling
,
Wuhan Iron and Steel University
,
Wuhan 430081
,
China
金属学报(英文版)
Based on the analyses of hot-deformation mechanism of the steel,a new constitutive equation describing the flow stress of steels was derived.The flow stress data of steel 55SiMnVB have been determined at 900—1200℃,strain rates of 1—100s~(-1)and true-strain of 0.08—0.8.An available evaluated formula on the flows tress has been obtained by means of non-linear regression.It can express clearly the physical process of hot-deformation.
关键词:
flow stress
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null
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TAO Zengyi LUO Jiaming Huazhong University of Science and Technology
,
Wuhan
,
China TAO Zengyi
,
Faculty of Metallic Materials
,
Dept.of Mechanical Engineering No.2
,
Huazhong University of Science and Technology
,
Wuhan 430074
,
China
金属学报(英文版)
The influence of laser surface melting and induction hardening on the surface structure,con- tact fatigue life and failure behaviour of the nodular cast iron has been investigated.The con- tact fatigue life can be improved by both laser treatment and induction hardening,but the fail- ure process and type are different from each other.The former is due to lumpy and deep spal- ling caused by crack propagation between the quenching zone and the substrate,and the latter is due to nubby and surface flaking caused by the oil wedged action into surface cracks.
关键词:
surface hardening
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null
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null
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XIE Changsheng SUN Peizhen ZHAO Jiansheng CHEN Yuqiu Huazhong University of Science and Technology
,
Wuhan
,
China XIE Changsheng Associate Professor
,
Department of Mechanical Engineering No.2
,
Huazhong University of Science and Technology
,
Wuhan 430074
,
China
金属学报(英文版)
The microstructures of Fe-Mn-Ni-Cr steels with medium carbon and the effect of alloy ele- ments on them have been investigated by means of X-ray diffraction quantitative phase ana- lyses,metallography and hardness tests.The volume fraction of martensite in steels quenched at 1100℃ can be expressed as: f_M~(1100)=162.643-15.482Mn-7.36Ni-4.286(Cr+Mo+V) Based on this expression,the quasi-equilibrium microstructure diagram has been obtained.It is shown that the effect of Mn on the austenite stability is greater than that of Ni.The equiva- lent [Ni]=2.104Mn+Ni and equivalent [Cr]=Cr+Mo+V. The driving force for martensite transformation at M_s point has been calculated to he drastically decreased by element Mn.
关键词:
quasi-equilibrium microstructure diagram
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null
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null
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TAO Zengyi WANG Aihua ZHU Beidi DENG Shijun CHENG Xudong FU Jiangmin Huazhong University of Science and Technology Wuhan
,
430074
,
ChinaWuhan Research Institute of Material Protection
,
Wuhan
,
430000
,
China
材料科学技术（英文）
An alumina coating was developed on mild carbon steel by plasma spraying and then modified by laser remelting.Some characteristics of plasma sprayed ceramic coating before and after laser remelting,such as microstructure,wear resistance, heat shock resistance,hot corrosion property and bond strength,have been investigated in this paper.
关键词:
plasma spraying
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null
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