摘要
通过考虑临界应变以后的软化机制,构建了包括动态回复和动态再结晶过程的金属热成形分段流变应力数学模型。利用Gleeble3500热模拟试验机进行了X70HD抗大变形管线钢低应变速率到高应变速率下的单道次热压缩实验,获得了应力-应变曲线,并确定了基于Z参数的特征点、待定参数值,验证了模型不但在低应变速率下适用,在高应变速率下仍具备较高的准确性;建立了从动态再结晶开始到完成整个过程被考虑在内的再结晶动力学模型,通过与基于Johnson-Mehl-Avrami(JMA)方程求得的动态再结晶实际体积分数相比较,表明该动力学模型具有很高的精确度,可为抗大变形管线钢生产中的组织、性能预报提供理论依据。
By considering the softening mechanism after critical strain,a model of flow stress for metal hot forming including dynamic recovery and dynamic recrystallization process was established based on the critical strain. The flow stress behavior of X70 HD steel was investigated under different temperatures( 820 ℃ to 1100 ℃) and strain rates( 0. 01 s- 1to 50 s- 1) on a Gleeble-3500 thermo-simulation machine and the parameters of the model were identified by inverse analysis of the experimental stress-strain curves obtained from the hot compressive deformation. The error analysis of the flow stress model proves that the model has a good accuracy at high strain rates. A complete kinetics model of the pipeline steel characterized by DRX for instance is built and parameters are determined through analyzing and calculating the data of thermo-simulation. The examination shows that the predicted values are in good agreement with the experimental values,thus the dynamic recrystallization kinetics model can be used to predict the microstructure and properties of pipeline steel forming.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2015年第1期211-216,共6页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金(51304171)
河北省自然科学基金(E2013203248)
国家工程中心开放性课题资助项目(NECSR-201209)
关键词
抗大变形管线钢
流变应力模型
高应变速率
动力学模型
high deformation pipeline steel
flow stress model
high strain rate
dynamic recrystallization
