20CrMnTi结构钢热变形行为及其数学模型  

The Hot Deformation Behavior and Dynamic Recrystallization Model of 20CrMnTi Structural Steel

作　　者：张斌[1] 张鸿冰[2] 

机构地区：[1]宝钢集团上海第一钢铁有限公司技术中心,上海200431 [2]上海应用技术学院材料科学工程系,上海200052

出　　处：《上海交通大学学报》2003年第12期1826-1830,共5页Journal of Shanghai Jiaotong University

基　　金：上海市高等学校科学技术发展基金重点项目(03HZ01);国家自然科学基金资助项目(50275094)

摘　　要：利用Gleeble-1500热模拟实验机研究了20CrMnTi结构钢在温度为1223～1243K,变形速率为0.01～5s-1条件下的热变形行为.通过奥氏体再结晶动力学回归计算了20CrMnTi的形变激活能,以及峰值应力与变形温度、应变速率之间的关系;提出采用加工硬化率-应变(θ-ε)图可以准确地判断该钢发生动态软化的类型,并可以确定动态再结晶开始和结束以及最大软化率时所对应的应变.给出了反映该钢动态再结晶进行过程的动态再结晶状态图,以及动态再结晶开始时间和完全再结晶时间与形变温度的关系图,并回归出了20CrMnTi钢的再结晶动力学方程.The hot deformation behavior of 20CrMnTi steel was studied with a compression test by using Gleeble 1500 simulator at the temperature of 1 223~1 243 K and strain rate of 0.01~5 s^(-1). The deformation activation energy, the relationship between the peak stress, σ_p, with the deformed temperature and strain rate were calculated. A method was developed to determine the critical strain (ε_c) for DRX initiation, the strain for maximum softening rate (ε~*) and the steady strain (ε_s) by using the plot of work-hardening rate versus strain (θ-ε) curves. The dynamic recrystallization (DRX) state, the relationship of the initiation time and full DRX time with the deformed temperature were analyzed to access the DRX progress with different hot-working condition. The mathematical model of DRX kinetics of 20CrMnTi was (obtained).

关 键 词：结构钢 再结晶动力学 最大软化率 动力学方程 

分 类 号：TG312[金属学及工艺—金属压力加工]