ZHOU Lubin ZHANG Jie KANG Mokuang Northwest Polytechnic University
,
Xi'an
,
China ZHOU Lubin
,
Associate Professor
,
Dept.of Mater.Sci.and Eng.
,
Northwest Polytechnic University
,
Xi'an
,
China
金属学报(英文版)
The strain fatigue,impact fatigue and rotation beam fatigue behaviour of granular bainitic structure has been studied.The results show that the strain fatigue properties and the impact fatigue properties of granular bainite are superior to that of tempered martensite under the condition that the ultimate tensile strength is equal.The impact.fatigue life increases with in- creasing amount of granular bainite,because the M-A islands might retard the propagation of fatigue crack.The rotation beam fatigue properties of granular hainite are similar to that of tempered martensite.The relationship between.fatigue limit S_f,yield strength σ_y and frac- ture strength S_k may be expressed as S_f=4.651+0.1411(σ_y+S_k)
关键词:
granular bainite
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null
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CHAI Huifen WANG Liqin Xi'an Jiaotong Uuiversity
,
Xi'an
,
ChinaLAIRD Campell University of Pennsylvania
,
U.S.A.[Originally published in ACTA METALL SIN(CHINESE EDN)25(3)1989 pp A201—A206
,
Associate professor
,
Xi'an Jiaotong University
,
Xi'an
,
China
金属学报(英文版)
The evolution of dislocation structures in 6% prestrained steel 1018 during fatigue has been studied by TEM.The dislocations are quite movable,the loose cells quickly change to “checkboard”structures,in which the main cell walls lie about {100}.Then,the low energy dislocation structures i.e.dipolar walls and abyrinth structures are evolved.The characteristic of labyrinth and the orientation of dipolar walls are quite similar to fcc crystal.This indicates the energy state of system and the moving ability of dislocations are important factors affect- ing softening process,rather than the slip geometric characteristic of dislocations and details of dislocations.The decreasing in misorientation between adjoining cells and internal stress are discussed.
关键词:
steel 1018
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null
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SHI Deke LIU Junhai Xi'an Jiaotong University
,
Xi'an
,
China SHI Deke
,
Associate Professor
,
Department of Materials Science and Engineering
,
Xi'an Jiaotong University
,
Xi'an
,
China
金属学报(英文版)
The work hardening of Hadfield manganese steel arises mainly form two causes;1)a large amount of twinning makes perfect dislocations or Shockley dislocations to be blocked at the coherent twin boundaries.2)the deformation leads to strong unsymmetrical distortion due to the occurrence of a large number gf Mn-C pairs or Mn-vacancy carbon-carbon cluster.It has been demonstrated by TEM observation and internal friction tests.As deformation pro- ceeds,the slip constantly accomodates twinning shear giving rise to stress relaxation.Thus, the Hadfield steel exhibits both rapid work hardening and good ductility.
关键词:
twin
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null
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HU Guangli LIU Zhengtang WANG Ping HUA Wenjun KANG Mokuang Northwestern Polytechnical University
,
Xi'an
,
China HU Guangli
,
Associate Professor
,
Department of Materials Science and Engineering
,
Northwestern Polytechnical University
,
Xi'an
,
China
金属学报(英文版)
The variations of microstructures and mechanical properties of steels 15CrMnMoV, 18Mn2CrMoB,18Cr2Ni4W,30CrMnSi,30CrMnSiNi2 and 40CrMnSiMoV,which were tempered at different temperatures after austempering and continuous cooling at given rates, have been investigated.Based on the experimental results,the behaviour and mechanism of tempered bainite embrittlement(TBE)have been discussed.Finally,the theoretical and prac- tical basis for selecting the optimum tempering temperature of steels with bainite structure af- ter heat treatment are proposed.
关键词:
austempering
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null
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WANG Xike SHEN Ningfu CHEN Haisong Zhengzhou Institute of Technology
,
Zhengzhou
,
ChinaZHANG Haifeng Luoyang Research Institute for Ship Materials
,
Luoyang
,
ChinaGU Haicheng Xi'an Jiaotong University
,
Xi'an
,
China Professor
,
Research Centre for Materials
,
Zhengzhou Institute of Technology
,
Zhengzhou 450002
,
China
金属学报(英文版)
The depth profile of composition,chemical state of elements and morphology of as- received and activated amorphous Fe_(80)Zr_(12)B_8 alloy ribbons have been studied by means of Auger electron spectroscopy,X-ray photoelectron spectroscopy and scanning Auger microprobe combined with Ar ion bombardment.Both dull and free sides of the as- received ribbons were covered with an iron oxide layer.While a pronounced surface segregation and oxidation of B and precipitation of microcrystalline α-Fe particles were observed on both sides of activated ribbons,B and Zr were oxidized selectively in subsurface layer.On both sides of ribbons,a porous surface structure formed. The BET surface area was measured to be increasing from 0.11 to 2.68 m~2/g.The principal mechanism of in situ activation has been discussed.
关键词:
amorphous Fe_(80)Zr_(12)B8 alloy
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null
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null
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LIU Yumen HE Zhirong Xi'an Jiaotong University
,
Xi'an
,
China Professor
,
Dept.of Materials Science and Engineering
,
Xi'an Jiaotong University
,
Xi'an
,
China
金属学报(英文版)
The morphologic,substructural and crystallographic characteristics of martensite in steels 60 and 60Si2Mn have been investigated by means of optical and transmission electron microscopy combined with B-M phenomenological crystallographic theory.The average hab- it plane of martensite in medium carbon iron alloys is{225}_f.Experimental data on the habit plane and the orientation relationship between the austenite and martensite are in agreement with the B-M theoretical calculation of using the Bain strain and lattice invariant shear on (100)[011]_f.
关键词:
Medium carbon steel
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null
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null
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LIU Zhiguo CHEN Yong CAO Yanni Nanjing University
,
Nanjing
,
ChinaZHU Zhengsheng Shaanxi Iron and Steel Institute
,
Xi'an
,
China Professor
,
Dept.of Physics
,
Nanjing
,
University
,
Nanjing 210008
,
China
金属学报(英文版)
The microstructural evolution and precipitation hardening of an Elinvar alloy doped with Ti and Al during isothermal aging at 700℃ have been investigated by atom probe field ion microscopy and microhardness measurements.The γ′ precipiates are spherical and coherent with the matrix.The chemical composition of the precipitates are(Ni_(0.53)Fe_(0.47)_3 (Ti_(0.(?))Al_(0.4)). During aging,a Lifshitz-Wagner type dissolution and coarsening reaction of the precipitates has been observed,The hardness of the material varies with the aging time and reaches maxi- mum when the average diameter of the precipitates was about 11 nm.
关键词:
Elinvar alloy
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null
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null
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null
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XIA Zhenhai Hebei Institute of Technology
,
Tianjin
,
ChinaMAO Zhiying ZHOU Yaohe Northwestern Polytechnical University
,
Xi'an
,
China Doctor
,
Faculty of Foundry
,
Department of Mechanical Engineering No.2
,
Hebei Institute of Technology
,
Tianjin 300132
,
China
金属学报(英文版)
On the basis of fluid kinetics,a model for infiltration kinetics of liquid metals into fibre pre- fabricated composite has been proposed.The infiltration processing,together with the measurements of infiltrating velocity and permeability,for the C fibre-reinforced Al matrix composites have been studied.The model proposed seems to be in good agreement with the ex- perimental results.Two different infiltration modes,uniform and non-uniform,were found and a new technique was suggested.Thus,the quality composites of C fibre-reinforced Al may be made under low pressure regardless of non-wettability of liquid metal to the fibres.
关键词:
liquid metal
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null
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null
