摘要
利用Gleeble-1500热模拟试验机研究镍基高温合金K403在应变速率为0.01-10 s-1、温度为850-1 000℃条件下的高温拉伸变形行为,利用光学显微镜、扫描电镜、透射电镜等手段,分析拉伸变形后的显微组织及高温断裂机制。结果表明：随应变速率的增大,合金的峰值应力和断裂应力增大,断面收缩率和断裂应变则减小;而随变形温度的升高,合金的峰值应力和断裂应力降低,断面收缩率和断裂应变增大;850℃拉伸后变形组织中存在大量的位错胞状结构,随着变形温度的升高,变形组织中的位错密度减小;拉伸断口呈枝晶组织断裂特征,随着变形温度的升高,合金断裂方式由准解理断裂向沿晶断裂转变。
The high temperature tensile deformation and fracture behaviors of Ni- based superalloy K403 were studied using Gleeble-1500 thermo-simulation machine at the temperatures of 850 to 1 000 ℃ and strain rates of 0.01 to 10 s- 1. The optical microscope（OM）,scanning electron microscope（SEM）and transmission electron microscope（TEM）were employed to analyze the microstructure evolution of tensile deformation and fracture mechanism at high temperatures. The results show that with the increase of the strain rates,the peak stress and the breaking stress of the superalloys increase,while the reduction of area and the breaking strain decrease;with the increase of the deformation temperatures,the peak stress and the breaking stress decrease,and the reduction of area and the breaking strain increase. A mass of dislocation cells are formed in the deformed microstructure after the tensile deformation at 850 ℃,while with the increase of the deformation temperatures,the dislocation density in the deformed microstructure decreases. The tensile fracture surface is characterized by the dendritic structure fracture,and the fracture mechanism changes from quasi- cleavage fracture to inter- granular fracture with deformation temperature increasing.
出处
《兵器材料科学与工程》
CAS
CSCD
北大核心
2014年第6期25-28,共4页
Ordnance Material Science and Engineering
基金
国家自然科学基金重点项目(50935007)
国家"973"课题(2010CB731701)
西安市科技计划项目(CX12180-7)
关键词
K403镍基合金
高温拉伸
显微组织
断裂行为
Ni-based alloy K403
high temperature tensile
microstructures
fracture behavior
