Fe-V-C系奥氏体中VC析出动力学计算  

Thermodynamic computation of vanadium carbide precipitation in austenite of Fe-V-C

作　　者：李小明[1] 钟海林[1] 王学兵[1] 吴立志 况春江[1] 

机构地区：[1]安泰科技股份有限公司,北京100081 [2]河冶科技股份有限公司,石家庄050031

出　　处：《粉末冶金技术》2012年第3期167-170,199,共5页Powder Metallurgy Technology

基　　金：国家"十一五"科技支撑计划资助项目(2007BAE51B05);国家高科技发展计划资助项目(2012AA03A509)

摘　　要：以材料热力学及动力学为基础,以Fe-V-C三元系为研究对象,研究了1 130℃恒温条件下碳化物VC在奥氏体中从形核、长大到熟化的连续过程。各元素在碳化物-基体界面处达到局部平衡,根据基体成分以及每个碳化物颗粒的大小分别计算出生长速度。当碳化物生长进入熟化阶段,在Gibbs-Thomson效应作用下,小颗粒开始回溶,大颗粒继续长大,表现为总颗粒数量减少,平均半径变大;当保温时间达到1×104s时,析出量接近平衡状态,VC体积分数为1.51%、平均半径为0.72μm。Precipitation of vanadium carbides in austenite in Fe-V-C system were quantitatively calculated at 1 130℃.On the basis of precipitation thermodynamics and kinetics,continuous stages from nucleation to growth and coarsening of carbides were analyzed.A local equilibrium condition was used at the precipitate-matrix interface to derive the growth rate of each precipitate as a function of its size and the current matrix composition.When coarsening occurs,small carbides began to dissolve and big ones keep on growing because of the effect of Gibbs-Thomson,the radius of carbides increase while the number of carbides decreases.The results show that the system is almost in equilibrium state when the isothermal heat treatment time reaches 104 second,the volume fraction of carbides is 1.51% and mean radius is 0.72μm.

关 键 词：碳化物 析出 形核 热力学 动力学 

分 类 号：TQ530.2[化学工程—煤化学工程]