FU Changpu HAN Yong Shaanxi Mechanical Engineering Institute
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Xi'an
,
China FU Changpu
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associate professor
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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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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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