新型超超临界机组用叶片钢11Cr12Ni3Mo2VN的热变形行为  

The High-temperature Deformation Behavior of Novel 11Cr12Ni3Mo2VN Heat Resistant Steel for Ultra-supercritical Units

作　　者：吕鹏[1] 陈亚楠 关庆丰[1] 李姚君 许亮 丁佐军 LYU Peng;CHEN Yanan;GUAN Qingfeng;LI Yaojun;XU Liang;DING Zuojun(Department of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,China;Wuxi Parker New Materials Technology Co.Ltd.,Wuxi 214161,China)

机构地区：[1]江苏大学材料科学与工程学院,镇江212013 [2]无锡派克新材料科技股份有限公司,无锡214161

出　　处：《材料导报》2020年第4期113-117,共5页Materials Reports

基　　金：国家自然科学基金(51601071);江苏大学青年英才培育计划项目;江苏省博士后科研资助计划(2018K025B);江苏省研究生科研实践创新项目(KYCX18-2236)~~

摘　　要：通过Gleeble-3500热模拟试验机对11Cr12Ni3Mo2VN马氏体耐热钢进行等温热压缩实验,研究了其在变形温度T为900~1050℃、应变速率为0.001~10 s^-1条件下的热变形行为,确定了材料的热变形参数。通过对峰值应力的拟合建立了热变形本构方程,并对本构方程的准确性进行了验证,发现建立的本构方程能够准确预测材料在高温变形时的流变应力。根据ln[sinh(ασ)]-lnε曲线求得材料的热变形表观激活能Q为450.988 kJ/mol。以动态材料模型和Murthy失稳判据为理论基础绘制了热加工图,结合应力-应变曲线,确定了11Cr12Ni3Mo2VN耐热钢的最佳加工工艺参数:加工温度为980~1050℃,应变速率为0.1 s^-1或更小。还利用光镜研究了加工温度、应变速率等热变形参数对材料微观组织演变的影响。结果表明,热变形温度和应变速率都会影响11Cr12Ni3Mo2VN耐热钢的动态回复和动态再结晶机制。加工温度起决定性作用,在温度较低的条件下,材料的动态回复机制占主导;随着温度的升高,材料的软化机制以动态再结晶为主。应变速率对动态再结晶晶粒尺寸的影响较大,低应变速率有利于动态再结晶的充分进行,晶粒大小更加均匀,材料在热变形后的性能更加优异。The purpose of this paper was to investigate the thermal deformation behavior of 11Cr12Ni3Mo2VN martensite heat-resistant steel and establish the optimal thermal deformation processing parameters of the material.In this paper,11Cr12Ni3Mo2VN martensite heat-resistant steel was isothermal heat-compressed by Gleeble-3500 thermal simulation tester at the condition of the temperatures ranging from 900℃to 1050℃and strain rate in the range of 0.001-10 s^-1.Established a constitutive equation by fitting the peak stress and verified the accuracy of the constitutive equation.It was found that the established constitutive equation have a high prediction precision on the flow stress of the material.By calculating and analysing of the experimental data,the apparent activation energy(Q)was determined to be 450.988 kJ/mol.Drawn the thermal processing maps based on the dynamic material model and Murthy's instability criterion.The optimal processing parameters of 11Cr12Ni3Mo2VN heat-resistant steel was determine by the thermal processing maps and the stress-strain curves.The specific parameters were as follows:the processing temperature from 980℃to 1050℃and the strain rate of 1 s^-1 or less.The effects of the thermal deformation parameters such as temperature and strain rate on the microstructure evolution of the material were studied through OM.The results show that the temperature and strain rate have a great influence on the generation and degree of dynamic recovery and recrystallization.The processing temperature plays a decisive role in the evolution of the microstructures,the dynamic recovery dominates at low temperatures,and the degree of dynamic recrystallization rose as the temperature increased.In addition,the strain rates have a great influence on the size of dynamically recrystallized grains.The low strain rate is beneficial to the full division of dynamic recrystallization,the grain size is more uniform,and the material has more excellent performance after thermal deformation.

关 键 词：马氏体耐热钢 11Cr12Ni3Mo2VN 热变形 本构方程 热加工图 动态再结晶 

分 类 号：TG142.73[一般工业技术—材料科学与工程]