摘要
利用SEM和TEM,对固溶强化合金Hastelloy C-276的初始组织和在650℃、不同拉应力下持久断裂试样进行显微组织分析。结果表明:试样的断口以典型的韧窝形貌为主,局部有少许晶间断裂现象,显示出C-276合金具有良好的高温韧性。在C-276合金的初始组织中,有退火孪晶和大量位错存在;在经受高应力拉伸过程中,晶体内产生大量形变孪晶;同时,发现在晶界和晶内有细小弥散的析出物。因此,C-276合金在650℃下优越的高温持久抗力是固溶强化、沉淀强化以及可能的孪晶强化综合作用的结果。
The microstructure of solid solution strengthened Hastelloy C-276 alloys before and after ruptured at 650 oC under different tensile stresses was studied by SEM and TEM.The results show that the fracture surface displays typical dimple morphology,with a few intergranular fractures.It can be concluded that the C-276 alloy has very good high-temperature toughness.A few annealing twins and plenty of dislocations exist in the initial microstructure of C-276 alloy.And after persistent tensile experiments,a large number of deformation twins are formed in C-276 crystals.Moreover,many fine and dispersive precipitations are also formed in the grain boundary and intragranular.Therefore,a good high temperature stress rupture performance of the Hastelloy C-276 alloy arises from co-effects of solid solution-strengthening,precipitation-strengthening and possible deformation twin-strengthening.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2010年第9期1571-1574,共4页
Rare Metal Materials and Engineering
基金
国家重点基础研究发展计划("973"计划)(2007CB209803)项目
长江学者和创新团队发展计划(IRT0720)
华北电力大学留学回国人员科研基金
