摘要
大尺寸涡轮盘锻件由于其特殊的生产工艺易形成混晶组织。采用光学显微镜、扫描电子显微镜、电子背散射衍射和拉伸试验等研究了GH4706合金涡轮盘锻件不同部位的显微组织及其对高温拉伸性能的影响。结果表明:轮缘、辐板、轮毂的平均晶粒尺寸分别为191、121、112μm,均出现了不同程度的混晶组织;随着晶粒尺寸的减小,γ′相的体积分数增大、平均尺寸减小。3个部位的晶粒取向差-频率分布均在60°出现峰值;合金组织中存在大量孪晶,且随着晶粒尺寸的减小,孪晶数量减少。随着拉伸试验温度的升高,涡轮盘锻件不同部位的抗拉强度和屈服强度均下降,断后伸长率总体上升高,断裂模式从混合型断裂转变为韧窝断裂。
Large-size turbine disc forgings are prone to formation of mixed grain structure due to their specific production process.The microstructures of different parts of GH4706 alloy turbine disc forgings and their effect on high-temperature tensile properties were studied by optical microscope,scanning electron microscope,electron back scatter diffraction and tensile test.The results showed that the average grain size of the flange,web plate and hub were 191,121 and 112μm,respectively,they all exhibited different degrees of mixed grain structure;and theγ′phase increased in volume fraction and decreased in average size with the decrease of grain size.The misorientation-frequency distributions of grains in the three parts all showed a peak at 60°;there were a large number of twins in the alloy,and the number of twins decreased with the decrease in grain size.As the tensile test temperature increased,the tensile strength and yield strength of different parts of the turbine disc forgings decreased,the elongation increased overall,and the fracture mode changed from mixed fracture to dimple fracture.
作者
侯翔益
徐烨玲
段然
王冲
黄烁
廉心桐
HOU Xiangyi;XU Yeling;DUAN Ran;WANG Chong;HUANG Shuo;LIAN Xintong(School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China;Gaona Aero Material Co.,Ltd.,Beijing 100081,China;School of Materials Science and Engineering,Northeastern University,Shenyang Liaoning 110004,China;Zhejiang Institute of Advanced Materials,Shanghai University,Jiaxing Zhejiang 314100,China)
出处
《上海金属》
2025年第5期21-26,共6页
Shanghai Metals
基金
国家重点研发计划(2022YFB3705105)。
关键词
GH4706
合金
混晶
显微组织
力学性能
GH4706 superalloy
mixed crystal
microstructure
mechanical property
