长期时效对低膨胀高温合金GH2909性能的影响  

Effect of Long-term Aging on Properties of Low Expansion Superalloy GH2909

作　　者：徐雄 李钊 万志鹏 韦康 王涛 张新房 XU Xiong;LI Zhao;WAN Zhipeng;WEI Kang;WANG Tao;ZHANG Xinfang(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;Science and Technology on Advanced High Temperature Structural Materials Laboratory,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China)

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]中国航发北京航空材料研究院先进高温结构材料重点实验室,北京100095

出　　处：《材料研究学报》2021年第5期330-338,共9页Chinese Journal of Materials Research

基　　金：重点实验室基金(6142903190205);国家自然科学基金(U1860206和51874023);中央高校基本科研业务费(FRF-TP-20-02B)。

摘　　要：将低膨胀高温合金GH2909分别在500℃、600℃和650℃时效2000 h,研究了长期时效对合金组织和性能的影响。结果表明:GH2909合金在550℃和600℃时效2000 h后其组织稳定性较高,强度略有提高,塑性基本不变。而在650℃时效2000 h后合金的拉伸强度明显降低,室温塑性下降,尤其是在室温下断面收缩率明显降低,但是高温塑性却显著提高。其原因是,GH2909合金在650℃长期时效过程中析出了大量贯穿晶粒且呈魏氏组织形貌的针状ε/ε″相,而强化相γ′相明显减少。同时,在该温度下γ′相明显长大且其稳定性下降。The microstructure and mechanical properties of a new type of low expansion superalloy GH2909 after long time exposure up to 2000 h at 550℃, 600℃ and 650℃ respectively were investigated. The results show that the alloy had a good microstructure stability and high mechanical properties,namely a slightly increase in strength and little change in plasticity, after aging at 550℃ and 600℃ for2000 h. However, after 2000 h aging at 650℃ the mechanical properties of the alloy dropped significantly: the strength at room temperature and high temperature decreased significantly, and the plasticity decreased at room temperature, especially the reduction of area at room temperature decreased sharply,but the plasticity increased significantly at high temperature. This is mainly due to the precipitation of a large number of needle-like ε/ε″ phases that penetrate the grains and have "Widmanstatten structure"-like morphology in the microstructure of the alloy during the long-term aging process at 650℃, resulting in a significant reduction in the quantity of strengthening phase γ′ phases. At the same time, the stability ofγ′ phase decreases at 650℃ and the size of γ′ phase increases significantly.

关 键 词：金属材料 GH2909合金 显微组织 长期时效 力学性能 

分 类 号：TG113[金属学及工艺—物理冶金] TG132.1[金属学及工艺—金属学]