摘要
采用RDL100型电子高温蠕变试验机、OM、SEM、TEM分析测试了新型Cr19Ni28TiN铁镍基合金的蠕变性能。蠕变试验结果表明,当加载应力减少到250 MPa时,出现明显稳态蠕变阶段;微观组织观察显示蠕变前奥氏体基体上均匀分布着少量的析出相,在600℃、300 MPa下蠕变后晶界和晶内都弥散析出大量的细小的TiN和M23C6;晶内析出相对位错产生钉扎作用,阻碍位错的移动,同时大量位错在共格晶界附近塞积,形成位错墙,提高了合金的蠕变强度。600℃、300 MPa条件下蠕变断裂分析表明,Cr19Ni28TiN合金断口平齐,存在一些较浅的撕裂韧窝,凹坑中的第二相成为裂纹的核心。
Creep property of a novel Fe-Ni based Cr19Ni28TiN alloy was investigated by means of RDLIO0 high temperature electrical creep machine, OM, SEM and TEM. The results show that the steady-state creep stage can be significantly observed when the loading stress decreased to 250 MPa. Microstructure observation revealed that a few precipitations distribute uniformly in austenite matrix before creep, and after creeping at 600 ℃ under 300 MPa, a lot of fine TiN and M23 C6 precipitations are formed in the grain boundary and inside. The intragranular precipitation impedes the movement of dislocation by pinning dislocation. Meanwhile, a large number of dislocation pile up and produce dislocation wall near the coherent grain boundary. As a result, the creep resistance of Cr19Ni28TiN alloy is remarkably enhanced. The creep fracture analysis shows that the fracture of the Cr19Ni28TiN alloy is even, with some shallow tearing dimple. The secondary precipitations in the pits act the initial core of crack.
出处
《金属热处理》
CAS
CSCD
北大核心
2015年第2期48-51,共4页
Heat Treatment of Metals
基金
国家高技术研究发展计划(863计划)(2012AA03A501)
江苏省产学研联合创新资金-前瞻性联合研究项目(BY2012169)
江苏大学高级人才项目(11JDG141
12JDG066)
