新型节镍奥氏体耐热钢的亚动态再结晶行为

Metadynamic recrystallization behavior of a novel austenite heat resistant stainless steel

在Gleeble-3800热模拟试验机上利用双道次热压缩实验,研究新型节镍奥氏体耐热不锈钢21Cr-11Ni-N-RE在变形温度950~1 150℃、应变速率0.1~10 s^-1,道次间保温时间为0.5~30 s的亚动态再结晶行为。建立亚动态再结晶的动力学模型,并将预测值与试验值进行比较。研究结果表明：试验钢易发生亚动态再结晶,随着道次间保温时间的延长、应变速率的增大和变形温度的升高,材料亚动态再结晶体积分数迅速增大;预应变超过峰值应变后,应变继续增大对亚动态再结晶体积分数的影响十分有限。21Cr-11Ni-N-RE耐热不锈钢的亚动态再结晶激活能Qmdrx为130.417 k J/mol,模型预测值与试验值吻合较好。

The metadynamic recrystallization（MDRX） behavior of a novel 21Cr-11Ni-N-RE austenite heat resistant stainless steel was studied by Gleeble-3800 thermal simulation testing machine, and using double hit compression experiments at temperature of 950~1 150 ℃, strain rate of 0.1~10 s^-1 and inter-pass time of 0.5~30 s. According to the present experimental results, the kinetic equation for the MDRX of 21Cr-11Ni-N-RE austenite heat resistant stainless steel was proposed. Comparison between the experimental and the predicted results was carried out. The results show that the metadynamic volume fraction rapidly increases with the increase of delay time, deformation temperature and strain rate. The pre-strain（beyond the peak strain） has little influence on the MDRX behaviors in 21Cr-11Ni-N-RE. The sub dynamic recrystallization activation energy of 21Cr-11Ni-N-Re heat resistant stainless steel is 130.417 k J/mol. A good agreement between the experimental and the predicted results is obtained, which has verified the developed models.