Acta Metallurgica Sinica (English Letters) ›› 1993, Vol. 6 ›› Issue (3): 168-171.

• Research paper • Previous Articles     Next Articles

RELATIONSHIP BETWEEN CREEP PROPERTIES AND STRUCTURE OF STEEL 20Cr11MoVNbNB

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   

  • Received:1993-06-25 Revised:1993-06-25 Online:1993-06-25 Published:2009-10-10

Abstract: 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,

Key words: 20Cr11MoVNbNB, heat-resisting steel, creep, creep hardness, creepactivation energy