Effect of rare earth alloying on creep rupture of economical 21Cr-11Ni-N heat-resistant austenitic steel at 650 ℃  

作　　者：陈雷 龙红军 刘鑫刚 金淼 马筱聪 

机构地区：[1]National Engineering Research Center for Equipment and Technology of Cold Strip Rolling,Yanshan University [2]School of Mechanical Engineering,Yanshan University

出　　处：《Journal of Rare Earths》2016年第4期447-452,共6页稀土学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(51101136);Natural Science Foundation of Hebei Province(E2012203013);College Science and Technology Research Project of Hebei Province,China(QN2014107);College Innovation Team Leader Training Program of Hebei Province,China(LJRC012)

摘　　要：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.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.

关 键 词：heat-resistant austenitic steel rare earths alloying creep rupture 

分 类 号：TG142.73[一般工业技术—材料科学与工程] O346.1[金属学及工艺—金属材料]