含硼冷镦钢10B21热变形过程中的静态再结晶行为

Static recrystallization behavior of boron⁃containing cold heading steel 10B21 during hot deformation

在Gleeble-1500热模拟机上对10B21冷镦钢进行单道次压缩试验,研究了变形温度(950、1000℃)、变形速率(0.1、1、10 s-1)、预应变(0.10、0.15、0.20)、初始晶粒尺寸和间隙时间对10B21冷镦钢静态再结晶行为的影响。对不同变形条件下的奥氏体晶粒进行观察,并构建了10B21冷镦钢静态再结晶动力学模型及晶粒尺寸模型。结果表明,静态再结晶体积分数与变形温度、变形速率、预应变、间隙时间呈正相关;静态再结晶晶粒尺寸与变形温度、初始晶粒尺寸呈正相关,与变形速率、预应变呈负相关。通过计算获得10B21冷镦钢静态再结晶激活能为221036 J/mol,晶粒尺寸模型试验值与计算值的相关系数R^(2)=0.99,该模型预测值准确率较高。

A single pass compression test was carried out on 10B21 cold heading steel by using Gleeble⁃1500 thermal simulator.The effects of deformation temperature(950,1000℃),deformation rate(0.1,1,10 s-1),pre⁃strain(0.10,0.15,0.20),prior grain size and interval time on the static recrystallization behavior of the 10B21 cold heading steel were studied.The austenite grains under different deformation conditions were observed,and the kinetic model of static recrystallization and the grain size model of the 10B21 cold heading steel were established.The results show that the volume fraction of static recrystallization is positively correlated with the deformation temperature,deformation rate,pre⁃strain and interval time.The static recrystallization grain size is positively correlated with deformation temperature,prior grain size,and negatively correlated with deformation rate and pre⁃strain.The static recrystallization activation energy of the 10B21 cold heading steel is 221036 J/mol.The correlation coefficient R^(2)=0.99 between the experimental value and the calculated value of the grain size model indicates that the accuracy of the predicted value of the model is high.