首页|铸造镍基高温合金K417G中高温拉伸断裂机理研究

铸造镍基高温合金K417G中高温拉伸断裂机理研究

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  • 国家科技期刊平台
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  • NSTL
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研究了高温合金K417G热等静压热处理后700℃和950℃时拉伸的断裂机制，使用万能试验机进行中高温拉伸试验，通过扫描电子显微镜对组织、断口形貌、断口纵截面进行观察。结果表明:热处理后试样枝晶形貌明显，枝晶干上γ'相立方度较高，尺寸为0。4～0。5 μm，且排列整齐，枝晶间有尺寸为1。5～2。6 μm的花瓣形γ'相析出。与700℃时试样的拉伸性能相比，950℃时抗拉强度降低了46。3%，而伸长率提高了200%，这说明高温拉伸强度降低，塑性增加。中温拉伸时，枝晶间长条形碳化物是断裂的主要裂纹源及扩展通道。而高温拉伸时，晶界处的碳化物、共晶成为裂纹源，裂纹沿晶界扩展，形成了沿晶断裂形貌。
Study on Tensile Fracture Mechanism of Cast Nickel-Based Superalloy K417G at Medium-High Temperature
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.

superalloyK417Ghot isostatic pressing heat treatmenthigh-temperature tensilefracture mechanism

鲍俊、玄伟东、樊志明、曹后帆、李寒松、王保军、任忠鸣

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中国航发商用航空发动机有限责任公司,上海 200241

上海大学省部共建高品质特殊钢冶金与制备国家重点实验室,上海 200444

高温合金 K417G 热等静压热处理 高温拉伸 断裂机理

国家自然科学基金国家自然科学基金上海市经信委工业强基项目航空科学基金重点项目上海市商用飞机发动机联合创新项目

5227438692060104GYQJ-2022-2-022022Z0470S6001AR966

2024

铸造
沈阳铸造研究所 中国机械工程学会铸造分会

铸造

CSTPCD
影响因子：0.499
ISSN：1001-4977
年,卷(期)：2024.73(4)
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