GAO Yan LI Dejun CAO Zhiben Dalian University of Science and Technology
,
Dalian
,
Liaoning
,
China LI Dejun
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Lecturer
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Department of Materials Engineering
,
Dalian University of Science and Technology
,
Dalian
,
Liaoning
,
China
金属学报(英文版)
The microstructure of Cr_(25)Ni_(20)stainless steel under plastic deformation up to 50% has re- vealed an even distributed twins,micro-twins and deformation bands.The σ-phase formation in 800℃ aged specimens is accelerated by its nucleation at either deformation twins or recrystallized grain boundaries under less or more deformation respectively.In the recrystallized zone,the recrystallization is prior to the precipitation of σ-phase.Although recrystallization may accelerate the formation of σ-phase,it is not essential.The twins and micro-twins produced by deformation may also provide the additional nucleation sites.
关键词:
plastic deformation
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GUO Chengyan Jilin Institute of Technology
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Changchun
,
ChinaGOTO Takashi HIRAI Toshio Tohoku University
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Japan Associate Professor
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Department of Materials Engineering
,
Jilin Institute of Technology
,
Changchun 130012
,
China
金属学报(英文版)
Investigation was made of the deposited rate,surface morphology and crystal pre- ferred orientation of the dense TiC coating onto austenitic stainless steel in relation with CH_4/TiCl_4 mole ratio and temperature adopted in CVD processing. When the CH_4/TiCl_4 ratio is low or high,the preferred orientation may be(220)or(200),respec- tively,which is mainly dependent on the equilibrium concentration of active C in vapour phase.
关键词:
preferred orientation
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null
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FU Changpu HAN Yong Shaanxi Mechanical Engineering Institute
,
Xi'an
,
China FU Changpu
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associate professor
,
Department of Materials Engineering
,
Shaanxi Mechanical Engineering Institute
,
Xi'an 710048
,
China
金属学报(英文版)
Studies were made of the effect of tempering at temperatures from 25 to 750℃ for 0.5 to 100 h on changes of hardness,precipitated phase and its alloying element content as well as activation energy of tempering for quenched steel 20Cr11MoVNbNB.Tempering of the steel at temperatures below 400℃ may be controlled by the diffusion of C atoms in α-Fe,and above 400℃,by diffusion of Cr,also Mo or V,in α-Fe.
关键词:
steel 20Cr11MoVNbNB
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null
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TIAN Baohong ZHENG Shi'an WU Lei Luoyang Institute of Technology
,
Luoyang
,
China ZHENG Shi'an
,
associate professor
,
Department of Materials Engineering
,
Luoyang Institute of Technology
,
Luoyang 471039
,
China
金属学报(英文版)
Determination was carried out of fatigue crack propagation rate of steel 65Cr5Mo3W2VSiTi (LM2)with various bainite contents and M/B duplex structure tempered at various tempera- tures.The threshold value of fatigue for each processing was estimated by experimental data. The mechanism for fatigue crack propagation of M/B duplex structure in steel LM2 seems to be non-continuous.The calculated fatigue crack micro-propagation rates are found to agree with the experimental data.
关键词:
duplex structure
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ZHANG Junshan CHEN Weixing CAO Zhiben Dalian University of Technology
,
Dalian
,
China Associate Professor
,
Department of Materials Engineering
,
Dalian University of Technology
,
Dalian
,
China
金属学报(英文版)
Creep behavior of Fe-15Cr-25Ni alloys with different grain boundary features has been in- vestigated at 850 and 950℃ and in stress range of 14.7~78.5 MPa.The single phase alloy exhibits typical recovery creep characteristics,and for the alloy in which M_(23)C_6 carbides densely precipitate at grain boundaries,the creep rate dramatically decreases and creep behav- ior is also significantly different from the single phase alloy.When the carbides precipitate at grain boundaries,the dislocation density are higher and the size of subgrains near grain boundaries are smaller than those of single phase alloy.The creep mechanisms for two grain boundary features have been discussed.
关键词:
grain boundary feature
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