含Nb多元微合金钢的应变诱导析出行为

Strain-induced precipitation in an Nb-bearing multi-microalloyed steel

利用松弛法,在Gleeble-1500热模拟机上测定了多元微合金钢的应力弛豫曲线,并采用萃取复型技术跟踪了析出物的长大过程。实验结果表明:应力弛豫曲线分为三个阶段,分别对应析出的形核、长大和粗化;在850℃变形后等温弛豫60～200s时,应变诱导析出颗粒的尺寸仍然小于10nm,析出相为复杂的(Nb,Ti,Mo)(C,N)。

With stress relaxation method, the relaxation curves were obtained with the aid ot Gleeole-1500 simulator. Meantime, the carbon extraction replica technique was used to follow the growth process of precipitates. The experiment results indicate that the stress relaxation curve is divided into two stages, corresponding to the nucleation, growth and coarsening of precipitates. The size of strain-induced precipitates is less than 10nm during relaxed for 60-200s after deformation at 850℃. The precipitates are complex carbonitrides （Nb,Ti,Mo）（C,N）.