摘要
采用两种不同浇注温度(1440℃和1520℃)制备了K439B合金,研究了合金晶粒组织、枝晶形貌及相组成,分析了浇注温度对合金显微组织与性能的影响。结果表明:当浇注温度为1440℃时,合金存在个别粗大晶粒,晶粒尺寸均匀性较差,二次枝晶臂间距为53. 0μm,合金的室温抗拉强度和伸长率分别为1169. 0 MPa和7. 4%,815℃/379 MPa持久寿命为71. 0 h;当浇注温度提高至1520℃时,合金晶粒尺寸略有增加,尺寸均匀性有所改善,二次枝晶臂间距提高至61. 2μm,枝晶间隙减小,组织变得致密,同时在晶界析出颗粒状M23C6型碳化物,室温抗拉强度与伸长率分别提高至1204. 0 MPa和10. 0%,815℃/379 MPa持久寿命达到124. 6 h。
K439B superalloy were prepared at two different casting temperatures ( 1440 ℃ and 1520℃). The grain structure, dendritic morphology and phase composition of the alloy were studied. The effect of casting temperature on the microstructure and properties of the alloy was analyzed. The results show that when the casting temperature is 1440 ℃, there are some coarse grains in the alloy, the grain size uniformity is poor, the secondary dendritic arm spacing is 53.0μm, the tensile strength and elongation of the alloy at room temperature are 1169.0 MPa and 7. 4%, respectively, and the stress rupture life at 815 ℃/379 MPa is 71.0 h. When the casting temperature is increased to 1520℃, the grain size and size uniformity of the alloy increase slightly, the secondary dendritic arm spacing is increased to 61.2 μm, the dendritic interspace decreases and the microstructure becomes dense. At the same time, the granular M23 C6carbides are precipitated at grain boundary, the tensile strength and elongation of the alloy at room temperature increase to 1204.0 MPa and 10.0%, respectively, and the stress rupture life at 815℃/379 MPa is improved to 124. 6 h.
作者
张雷雷
陈晶阳
骞磊
张明军
汤鑫
杨卿
ZHANG Lei-lei;CHEN Jing-yang;QIAN Lei;ZHANG Ming-jun;TANG Xin;YANG Qing(Science and Technology on Advanced High Temperature Structural Materials Laboratory, Beijing Institute of Aeronautical Materials, Beijing 100095, China;Faculty of Materials Science and Engineering, Xi’an University of Technology,Xi’an 710048,China)
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2019年第9期57-63,共7页
Transactions of Materials and Heat Treatment
基金
国家重点研发计划(2016YFB0701402)
中国航发科技创新平台项目(CXPT-2018-006)
先进高温结构材料重点实验室基金(61429030101131701)
