新型Cr20Ni30NbAl铁镍基合金的高温蠕变行为  

High temperature creep behavior of Fe-Ni based Cr20Ni30NbAl alloy

作　　者：程晓农[1] 高仕渊[1] 李冬升[1] 戴起勋[1] 姜杨[1] 王植栋[1] 邱宇[1] 都红[2] 

机构地区：[1]江苏大学材料科学与工程学院,江苏镇江212013 [2]江苏银环精密钢管股份有限公司,江苏宜兴214203

出　　处：《金属热处理》2013年第5期6-10,共5页Heat Treatment of Metals

基　　金：国家高技术研究发展计划(863计划)(2012AA03A501);江苏大学高级人才基金(11JDG141;12JDG066)

摘　　要：研究了铁镍基合金800H和Cr20Ni30NbAl的固溶组织以及600℃下不同应力的蠕变性能。利用OM、SEM和TEM对两种合金进行了对比研究,发现在相同的固溶处理条件下,两种合金晶界都析出(Cr,Fe)23C6,800H合金晶内弥散TiN颗粒直径约为60 nm,而Cr20Ni30NbAl合金由于Nb的加入在晶内弥散析出更细小的NbC颗粒,直径约5 nm,细小的弥散颗粒有效地提高了Cr20Ni30NbAl合金的蠕变强度。应用蠕变本构方程求的应力指数800H合金n0=8.79789,Cr20 Ni30 NbAl合金n1=17.58397。蠕变过程中,两种合金位错切割第二相均为Orowan机制,在600℃下Cr20 Ni30 NbAl合金具有更高的蠕变强度。800H合金断口表面出现带有小韧窝的沿晶断裂,Cr20Ni30NbAl合金断裂没有出现颈缩现象,断口呈现岩石状的沿晶断裂。Microstructure of Fe-Ni based alloys 800H and Cr2ONi30NbAl solutionized and their creep behaviors under different stress at 600℃ were studied. The results show that there are （Cr, Fe）23 C6 particles precipitated in grain boundary both of the 800H alloy and Cr2ONi30NbAl alloy under the same solution treatment conditions, lntragranular precipitation of TiN particles with size of about 60 nm is found in the 800H alloy, and fine dispersive NbC particles with size of about 5 nm is found in FeCr2ONi30NbA1 alloy due to the addition of Nb, which effectively improve the creep strength of the FeCr20Ni3ONbAl alloy. The FeCr20Ni30NbAl alloy has higher creep strength at 600 ℃, and its stress index nl is 17. 58397 while the 800H alloy＇s no is 8. 79789 calculated using of creep constitutive equation. The dislocation cutting the second phase is Orowan mechanism for both the alloys. Fracture surface of 800H alloy shows intergranular fracture with some small dimples, however that of the FeCr2ONi3ONbAl alloy presents intergranular fracture like rocks and without necking phenomenon.

关 键 词：Cr20Ni30NbAl铁镍基合金 显微组织 蠕变 断裂 

分 类 号：TG142.7[一般工业技术—材料科学与工程]