通过热压缩实验研究了21Cr^(-1)1Ni-N-RE节镍型奥氏体耐热钢的热力学行为和微观组织演变过程。通过对实验数据的回归分析,得到实验钢热变形激活能为451 k J/mol,应力指数为5.12。建立了热变形方程,确定了最大变形抗力和动态再结晶临界...通过热压缩实验研究了21Cr^(-1)1Ni-N-RE节镍型奥氏体耐热钢的热力学行为和微观组织演变过程。通过对实验数据的回归分析,得到实验钢热变形激活能为451 k J/mol,应力指数为5.12。建立了热变形方程,确定了最大变形抗力和动态再结晶临界应变预测模型。通过对微观组织演变过程的分析,得到了实验钢获得均匀细小的完全动态再结晶组织的热变形条件为1150℃和10 s^(-1)。展开更多
The effect of rare earth（RE） on creep rupture of economical 21Cr-11Ni-N heat-resistant austenitic steel was investigated at 650 °C under different stress levels. It was found that RE could increase the time to ...The effect of rare earth（RE） on creep rupture of economical 21Cr-11Ni-N heat-resistant austenitic steel was investigated at 650 °C under different stress levels. It was found that RE could increase the time to creep rupture, especially at long-term creep duration. The logarithm of the time to creep rupture（lgtr） was a linear function of the applied stress（σ）. RE addition was favorable to generating a high fraction of low-coincidence site lattice（CSL） boundaries which was a possible cause for improving the creep rupture resistance. The fracture surface of RE-added steel exhibited less intergranular cracks suggesting the alteration on the nature of grain boundaries due to the presence of RE. RE addition changed the morphology of the intergranular chromium carbides from continuous network shape to fragmentary distribution which was another cause for longer creep duration. These results strongly suggested that the effect of RE alloying played a crucial role in improving the creep rupture resistance.展开更多
文摘通过热压缩实验研究了21Cr^(-1)1Ni-N-RE节镍型奥氏体耐热钢的热力学行为和微观组织演变过程。通过对实验数据的回归分析,得到实验钢热变形激活能为451 k J/mol,应力指数为5.12。建立了热变形方程,确定了最大变形抗力和动态再结晶临界应变预测模型。通过对微观组织演变过程的分析,得到了实验钢获得均匀细小的完全动态再结晶组织的热变形条件为1150℃和10 s^(-1)。
基金Project supported by the National Natural Science Foundation of China(51101136)Natural Science Foundation of Hebei Province(E2012203013)+1 种基金College Science and Technology Research Project of Hebei Province,China(QN2014107)College Innovation Team Leader Training Program of Hebei Province,China(LJRC012)
文摘The effect of rare earth（RE） on creep rupture of economical 21Cr-11Ni-N heat-resistant austenitic steel was investigated at 650 °C under different stress levels. It was found that RE could increase the time to creep rupture, especially at long-term creep duration. The logarithm of the time to creep rupture（lgtr） was a linear function of the applied stress（σ）. RE addition was favorable to generating a high fraction of low-coincidence site lattice（CSL） boundaries which was a possible cause for improving the creep rupture resistance. The fracture surface of RE-added steel exhibited less intergranular cracks suggesting the alteration on the nature of grain boundaries due to the presence of RE. RE addition changed the morphology of the intergranular chromium carbides from continuous network shape to fragmentary distribution which was another cause for longer creep duration. These results strongly suggested that the effect of RE alloying played a crucial role in improving the creep rupture resistance.
