铸造2024，Vol.73Issue(4)：476-480,5.
铸造镍基高温合金K417G中高温拉伸断裂机理研究
Study on Tensile Fracture Mechanism of Cast Nickel-Based Superalloy K417G at Medium-High Temperature
摘要
Abstract
The fracture mechanism of the K417G high-temperature alloy under tensile conditions at 700℃and 950℃after hot isostatic pressing heat treatment was studied.Tensile tests at elevated temperatures were conducted using a universal testing machine,and observations of microstructures,fracture surfaces,and longitudinal sections were carried out through scanning electron microscopy.The results reveal that the dendritic morphology of the samples after heat treatment is pronounced,with a high degree of cuboidal γ'phase on the dendrite branches,measuring 0.4-0.5 μm and arranged in an orderly fashion.Petal-shaped γ'phase with sizes ranging from 1.5-2.6 μm precipitates between the dendrites.Comparing the tensile properties of samples at 950℃to those at 700℃,the tensile strength decreases by 46.3%,while the elongation increases by 200%.This indicates a reduction in high-temperature tensile strength and an increase in plasticity.During moderate-temperature tensile testing,elongated carbides between the dendrites serve as the primary crack initiation and propagation paths.In contrast,during high-temperature tensile testing,carbides at grain boundaries and eutectic constituents act as crack initiation sources,with cracks propagating along grain boundaries,forming a transgranular fracture morphology.关键词
高温合金/K417G/热等静压热处理/高温拉伸/断裂机理Key words
superalloy/K417G/hot isostatic pressing heat treatment/high-temperature tensile/fracture mechanism分类
矿业与冶金引用本文复制引用
鲍俊,玄伟东,樊志明,曹后帆,李寒松,王保军,任忠鸣..铸造镍基高温合金K417G中高温拉伸断裂机理研究[J].铸造,2024,73(4):476-480,5.基金项目
国家自然科学基金(52274386,92060104) （52274386,92060104）
上海市经信委工业强基项目(GYQJ-2022-2-02) （GYQJ-2022-2-02）
航空科学基金重点项目(2022Z0470S6001) （2022Z0470S6001）
上海市商用飞机发动机联合创新项目(No.AR966). （No.AR966）
