Q690低碳微合金钢热变形行为及动态再结晶临界应变  

Behavior of hot deformation and critical strain for dynamic recrystallization of a Q690 low carbon microalloyed steel

作　　者：谭智林[1,2] 向嵩[1,2] 

机构地区：[1]贵州大学材料与冶金学院,贵州贵阳550003 [2]贵州省材料结构与强度重点实验室,贵州贵阳550003

出　　处：《材料热处理学报》2013年第5期42-46,共5页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金项目(50901022)

摘　　要：利用Gleeble-3800数字控制热/力模拟试验机对Q690低碳微合金钢进行高温单道次热压缩实验,研究了不同变形温度(850～1150℃)、应变速率(0.01～30 s-1)条件下的热变形行为。采用峰值应力和饱和应力共同描述流变应力,确定了实验钢热变形激活能Q=356.05 kJ/mol,数值模拟回归出了实验钢的热变形本构方程。根据应变硬化率和应力的关系,确定了动态再结晶的临界应变值及其与Zener-Hollomon因子的关系式。The hot deformation behavior of Q690 low carbon microalloyed steel was studied by compression testing on a Gleeble-3800 digital control heat/force simulation test machine at 850-1150 ℃ and true strain rate range from 0. 01 s^-1 to 30 s^-1. The hot deformation activation energy of 356. 05 kJ/mol is determined and constitutive equation for hot deformation of the steel is obtained by characterizing the flow stress using both the peak stress and steady-state stress. Based on the relationship between strain hardening rate and true stress, the critical strain is determined, and a equation characterizing the relationship between the critical strain and Zener-Hollomon factor is derived.

关 键 词：Q690低碳微合金钢 动态再结晶 本构方程 临界应变 

分 类 号：TG142.33[一般工业技术—材料科学与工程]