Zhang Lei, Feng Xiao, Wang Xin, Liu Changyong
Key Laboratory for Advanced Materials Processing Technology of Ministry of Education, Tsinghua University, Beijing, China.
PLoS One. 2014 Nov 6;9(11):e102687. doi: 10.1371/journal.pone.0102687. eCollection 2014.
The nitrogen-containing austenitic stainless steel 316LN has been chosen as the material for nuclear main-pipe, which is one of the key parts in 3rd generation nuclear power plants. In this research, a constitutive model of nitrogen-containing austenitic stainless steel is developed. The true stress-true strain curves obtained from isothermal hot compression tests over a wide range of temperatures (900-1250°C) and strain rates (10(-3)-10 s(-1)), were employed to study the dynamic deformational behavior of and recrystallization in 316LN steels. The constitutive model is developed through multiple linear regressions performed on the experimental data and based on an Arrhenius-type equation and Zener-Hollomon theory. The influence of strain was incorporated in the developed constitutive equation by considering the effect of strain on the various material constants. The reliability and accuracy of the model is verified through the comparison of predicted flow stress curves and experimental curves. Possible reasons for deviation are also discussed based on the characteristics of modeling process.
含氮奥氏体不锈钢316LN被选为核主管道材料，核主管道是第三代核电站的关键部件之一。本研究建立了含氮奥氏体不锈钢的本构模型。利用在900 - 1250°C的宽温度范围和10(-3)-10 s(-1)的应变速率下进行等温热压缩试验获得的真应力-真应变曲线，研究了316LN钢的动态变形行为和再结晶。本构模型是通过对实验数据进行多元线性回归，并基于阿累尼乌斯型方程和齐纳-霍洛蒙理论建立的。通过考虑应变对各种材料常数的影响，将应变的影响纳入所建立的本构方程中。通过比较预测的流动应力曲线和实验曲线，验证了模型的可靠性和准确性。还根据建模过程的特点讨论了偏差的可能原因。
