材料期刊网

为研究静态再结晶过程中析出相对组织的细化作用,选取先前研究的V-N非调质钢作为试样,在Gleeble-1500D热模拟机上进行单道次与双道次压缩实验,计算了不同等温时间下的再结晶分数,采用带有STEM附件、INCA能谱仪及GIF能量过滤器的透射电镜JEM-2100F分析了析出相。结果表明：道次等温期间奥氏体中析出相主要为尺寸在55～140 nm的（Ti,V）（C,N）;相变冷却期间铁素体中析出相则为细小的长22～100 nm、宽13～39 nm的VC。静态再结晶与析出相相互竞争、共同细化组织。等温时间较短,静态再结晶起主要细化作用;析出相数量随等温时间延长而增加,使静态再结晶出现停滞平台;等温时间较长,奥氏体局部出现的溶质贫乏区促进了晶内铁素体形核,使组织细化。

In order to study the effect of precipitation on the refinement of microstructure during static recrystallization,a non-quenched and tempered V-N steel was employed to conduct single-pass and double-pass compression experiments on a Gleeble-1500D hot deformation simulator and the static recrystallization fraction at different isothermal time was calculated.The precipitates were analyzed by means of TEM,EDS analysis and energy filtering.The results show that the precipitates in austenite are mainly（Ti,V）（C,N） with size of 55 to 140 nm during isothermal between passes and the precipitates during cooling and phase transformation are mainly vermicular-shaped VC with length 22 to 100 nm and width of 13 to 39 nm.Static recrystallization and precipitation competifively occurs and both refines the microstructure.Static recrystallization plays a dominant role for microstructure refinement during shorter isothermal,and the amount of precipitates,increases with isothermal time increasing,which leads to retardation plateau in the static recrystallization fraction-isothermal time curve.Locally solute-poor regions in austenite are formed with isothermal time increasing further,which expedites the nucleation of intragranular ferrites and refines the microstructure.