Zr--4合金應力松弛過程中的熱激活變形與動態(tài)應變時效

1、452Vol.45No.220092173177ACTAMETALLURGICASINICAFeb.2009pp;(3);(4),.,.,t=0t=slnt+c(t>0)(1),.,.(473873K)15,t;0;s.(1)tcZr4,.;.,.,.,Zr4.12mmZr4,(,%):Sn1.45,Fe0.21,Cr0.11,O0.12,Zr.,MTS809A/T(25kN).,2.0×103s10.02,900s;0.05,900s;0.08900s.1.873K,MTS653,±1K.,500400aPM300,ssertS200100

2、0.000.020.040.060.080.10Strain1Zr4Fig.1ExperimentalcurvesofstressrelaxationfortheZr4alloy(relaxation900s,temperaturerange:RT873K),.,.,1dtp=e=E·dt(2),p,e;E.(1)dtsdt=t(3)1dp=E·tsdt=E·t(4)(4).30.08)(0.02,0.05,.,100600s.,623K(3ab)573K(3c)10080aP60M402002004006008001000t, sFig.2Relationshi

3、pbetweenstressreduction(0t)andrelaxationtimet100200300400500600t, sFig.3Variationsofplasticdeformationratepwithrelax-ationtimetatdierenttemperaturesandstrainsof0.02(a),0.05(b)and0.08(c).(0900)/0,4.900(900s).,623K(0.020.05)573K(0.08),.,623K.,.623K,.;,.,.,.,.,.v¯G9v¯=v0exp(GkT)(5),kBoltzmann

4、;T;v0,.1017645p=mbv¯/M(6)m,;bBurgers;MTaylor,.,b=3.23×1010m11,M=412.(5)(6)p=0exp(GkT)(7),0,.(G0),G0=G+blR/M(8),;lR;blR(V),13,V=blR=G/MT(9)(7),V= G lnp/MT=kT/M T(10),.,.,.,dt=d(11)(2),(8)(7),(11)d (GV/M)dt=E0exp0kT(12),(1).(4),dlnp1dt=t(13)(3),(11)(13)dlnp1d=s(14)(14)(10),V=kT lnp/M T=MkTs(

5、15)(15).5,Zr4.Burg-ers(b3).623573K,.,623K.,.,.,(3).Zr4(4).5:,;(373K),.,.,.,Zr4.,.,.,.14,.b,emulovnoitavitcA300400500600700800900Temperature, K5Fig.5Evolutionsofactivationvolumewithtemperatureatdierentstrains2:Zr41774(1)Zr4,.Zr4,.(2):,;,Zr4623K;Zr4.1LeeMH,KimJH,ChoiBK,JeongYH.JAlloysCompd,2007;428:99

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