D0L:10.13374/.issn1001-053x.2013.08.003 第35卷第8期 北京科技大学学报 Vol.35 No.8 2013年8月 Journal of University of Science and Technology Beijing Aug.2013 稀土对T91耐热钢动态再结晶行为影响 文智)，易丹青)☒，王斌)，石绍清)，张燕可) 1)中南大学材料科学与工程学院，长沙4100832)华菱衡钢钢管研究院，长沙410083 ☒通信作者，E-mail:yioffice@mail.csu.edu.cn 摘要采用Gleeble-1500热/力模拟试验机进行压缩试验，研究了不同变形条件下微量稀土对T91耐热钢动态再结晶 行为的影响.分析绘制了稀土加入前后实验钢的真应力一真应变曲线、再结晶一温度-时间图、再结晶图及功率耗散图，并 计算了高温下实验钢的再结晶激活能.在变形温度为8501100℃，变形速率为0.004~10s-1变形条件下，变形温度越 高和变形速率越低，动态再结晶越容易发生.稀土加入会产生固溶强化，稀土元素与碳原子发生交互作用，且在晶界处 或晶界附近偏聚，使变形抗力与峰值应变均增大，再结晶激活能由354.6 kJ-mol-1提高到397.2 kJ-mol-1.另外，稀土 会显著推迟再结晶发生时间，扩大再结晶的时间间隔，推迟再结晶动力学过程. 关键词铁素体钢：耐热性：稀土：显微组织：动态再结晶：激活能 分类号TG142.73 Effect of rare earths on the recrystallization behavior of T91 heat- resistant steel WEN Zhi),YI Dan-ging)☒，WANG Bin),SHI Shao-ging2),ZHANG Yan-ke） 1)College of Materials Science and Engineering,Central South University,Changsha 410083,China 2)Research Institute for Hengyang Valin Steel Tube Plant,Changsha 410083,China Corresponding author,E-mail:yioffice@mail.csu.edu.cn ABSTRACT The effect of rare earths on the dynamic recrystallization behavior of T91 heat-resistant steel under different deformation conditions was investigated on a Gleeble-1500 thermo-mechanical simulator.The true stress-strain curves,recrystallization-temperature-time(RTT)map,dynamic recrystallization map and power dissipation map were drawn for the steels with and without rare earths.The recrystallization activation energies of these two kinds of steels at elevated temperatures were also calculated in this paper.It is found that under the deformation condition of the temperature of 850 to 1100 C and the strain rate of 0.004 to 10 s-1,dynamic recrystallization happens at higher temperatures and lower strain rates.Rare earths dissolve in the matrix,resulting in solid solution strengthening.Rare earth elements interact with carbon and segregate at grain boundaries or around the matrix,leading to the increasing of peak stress and peak strain as well as the improvement of recrystallization activation energy from 354.6 kJ-mol-1 to 397.2 kJ-mol-.In addition,rare earths delay the starting time of recrystallization greatly,extend the time interval of recrystallization,and postpone the recrystallization kinetic process. KEY WORDS ferritic steel;heat resistance;rare earths;microstructure;dynamic recrystallization;activation energy T91(9Cr-1Mo-V-Nb)钢是在9Cr-1Mo型耐热成本被广泛用于超临界锅炉耐热管道，在日本、欧 钢基础上，添加V、Nb、N等元素开发的新型耐热美等国被作为开发更高使用温度的铁素体耐热钢材 钢.该钢种因其高的热强性，良好的持久塑性、抗氧 的研究基准-4.但是，这种钢又属于难变形钢种， 化性和抗腐蚀性能，低的热膨胀系数和较低的生产 其化学成分复杂和合金元素含量高，在热变形过程 收稿日期：2012-08-13 基金项目：中南大学衡钢钢管研究院“提高高合金钢连铸管坯成材率的技术研究”子课题第 35 卷 第 8 期 北 京 科 技 大 学 学 报 Vol. 35 No. 8 2013 年 8 月 Journal of University of Science and Technology Beijing Aug. 2013 稀土对 T91 耐热钢动态再结晶行为影响 文 智1)，易丹青1) ，王 斌1)，石绍清2)，张燕可1) 1) 中南大学材料科学与工程学院，长沙 410083 2) 华菱衡钢钢管研究院，长沙 410083 通信作者，E-mail: yioffice@mail.csu.edu.cn 摘 要 采用 Gleeble-1500 热/力模拟试验机进行压缩试验，研究了不同变形条件下微量稀土对 T91 耐热钢动态再结晶 行为的影响. 分析绘制了稀土加入前后实验钢的真应力–真应变曲线、再结晶–温度–时间图、再结晶图及功率耗散图，并 计算了高温下实验钢的再结晶激活能. 在变形温度为 850∼1100 ℃，变形速率为 0.004∼10 s−1 变形条件下，变形温度越 高和变形速率越低，动态再结晶越容易发生. 稀土加入会产生固溶强化，稀土元素与碳原子发生交互作用，且在晶界处 或晶界附近偏聚，使变形抗力与峰值应变均增大，再结晶激活能由 354.6 kJ·mol−1 提高到 397.2 kJ·mol−1 . 另外，稀土 会显著推迟再结晶发生时间，扩大再结晶的时间间隔，推迟再结晶动力学过程. 关键词 铁素体钢；耐热性；稀土；显微组织；动态再结晶；激活能 分类号 TG142.73 Effect of rare earths on the recrystallization behavior of T91 heat￾resistant steel WEN Zhi 1), YI Dan-qing 1) , WANG Bin 1), SHI Shao-qing 2), ZHANG Yan-ke 1) 1) College of Materials Science and Engineering, Central South University, Changsha 410083, China 2) Research Institute for Hengyang Valin Steel Tube Plant, Changsha 410083, China Corresponding author, E-mail: yioffice@mail.csu.edu.cn ABSTRACT The effect of rare earths on the dynamic recrystallization behavior of T91 heat-resistant steel under different deformation conditions was investigated on a Gleeble-1500 thermo-mechanical simulator. The true stress-strain curves, recrystallization-temperature-time (RTT) map, dynamic recrystallization map and power dissipation map were drawn for the steels with and without rare earths. The recrystallization activation energies of these two kinds of steels at elevated temperatures were also calculated in this paper. It is found that under the deformation condition of the temperature of 850 to 1100 ℃ and the strain rate of 0.004 to 10 s−1 , dynamic recrystallization happens at higher temperatures and lower strain rates. Rare earths dissolve in the matrix, resulting in solid solution strengthening. Rare earth elements interact with carbon and segregate at grain boundaries or around the matrix, leading to the increasing of peak stress and peak strain as well as the improvement of recrystallization activation energy from 354.6 kJ·mol−1 to 397.2 kJ·mol−1 . In addition, rare earths delay the starting time of recrystallization greatly, extend the time interval of recrystallization, and postpone the recrystallization kinetic process. KEY WORDS ferritic steel; heat resistance; rare earths; microstructure; dynamic recrystallization; activation energy T91 (9Cr-1Mo-V-Nb) 钢是在 9Cr-1Mo 型耐热 钢基础上，添加 V、Nb、N 等元素开发的新型耐热 钢. 该钢种因其高的热强性，良好的持久塑性、抗氧 化性和抗腐蚀性能，低的热膨胀系数和较低的生产 成本被广泛用于超临界锅炉耐热管道，在日本、欧 美等国被作为开发更高使用温度的铁素体耐热钢材 的研究基准[1−4] . 但是，这种钢又属于难变形钢种， 其化学成分复杂和合金元素含量高，在热变形过程 收稿日期：2012–08–13 基金项目：中南大学衡钢钢管研究院 “提高高合金钢连铸管坯成材率的技术研究” 子课题 DOI:10.13374/j.issn1001-053x.2013.08.003