Nb,Ti和V对含Nb微合金钢热变形行为的影响

来源期刊：金属学报2010年第7期

论文作者：吴晋彬 刘国权 王浩

文章页码：838 - 843

关键词：Nb； Ti； V； 低碳含Nb微合金钢； 动态再结晶动力学； Avrami动力学曲线

Key words：Nb； Ti； V； low carbon Nb microalloyed steel； dynamic recrystallization kinetics； Avrami kinetics curve

摘    要：基于Nb,Ti和V含量不同的6种低碳含Nb微合金钢的热模拟实验数据,利用硬化速率-应力(θ-σ)曲线,准确确定了其发生动态再结晶的临界应变ε_c、峰值应变ε_p、临界应力σ_c、峰值应力σ_p和稳态应力σ_ss值.结果表明,峰值应力σ_p随Nb,Ti和V含量的增加而增大,6种实验钢发生动态再结晶的ε_c/ε_p的取值范围为0.50-0.65.采用σ-ε曲线法计算获得了动态再结晶的Avrami动力学曲线,与采用金相方法得到的动态再结晶动力学曲线比较接近.随着钢中Nb和Ti含量增加,动态再结晶的Avrami动力学曲线右移;Nb微合金钢中复合添加Ti和V则导致在更低的应变速率下才能发生动态再结晶.

Abstract: The characteristic values such as critical strainε_c,peak strain ε_p,critical stress σ_c,peak stress σ_p and steady-state stress σ_ss were obtained from work-hardening rate-flow stress (θ-σ) curves based on the thermal/mechanical simulation data of 6 microalloyed steels with different contents of Nb,Ti and V.The results show that the peak stress σ_p was raised with the increasing contents of Nb,Ti and V,while the ε_c/ε_p value for all the experimental steels are in the range of 0.50-0.65.Then the Avrami kinetic curves of dynamic recrystallization were calculated from σ-ε curves for the 6 steels,which are very similar to those curves obtained by metallographic methods. With the increase of content of Nb and Ti,the corresponding Avrami curve shifted to the right and the dynamic recrystallization kinetics were hindered;while simultaneously adding Ti and V into Nb microalloyed steel would lead to the dynamic recrystallization to be initiated at much lower strain rate.