Heat treatment for recycled material of DD494 alloy turbine blade

doi:10.13251/j.issn.0254-6051.2024.06.001

Abstract

Abstract: Effect of three types heat treatment processes on the microstructure, creep rupture properties and fracture mechanism of recycled material of the DD494 alloy turbine blade was studied. The initial melting temperature of the alloy was determined by metallographic observation. The effect of solution treatment temperature on the dissolution of γ/γ′ eutectic and γ′ phase morphology, and the effect of first aging heat treatment temperature on the size, quantity and distribution of γ′ phase were analyzed by using scanning electron microscope (SEM). The results show that the initial melting temperature of the alloy is between 1310 ℃ and 1315 ℃. After heat treatment at 1300 ℃ for 4 h followed by air cooling, the number of γ/γ′ eutectic and the size of γ′ phase are decreased compared to that of 1290 ℃ for 4 h followed by air cooling. Compared to single step solution, segmented solution treatment can reduce the eutectic content in the alloy. It is found that the higher first aging heat treatment temperature (1140 ℃ compared with 1080 ℃) causes the growth of primary γ′ phase and a large amount of fine secondary particles γ′ precipitated in the γ matrix. The optimal heat treatment process for the alloy is segmented solution treatment+high temperature first aging+secondary aging, i.e. 1280 ℃×1 h+1290 ℃×2 h+1300 ℃×6 h, AC+1140 ℃×3 h, AC+870 ℃×20 h, AC. The average creep rupture life of the alloy treated with the optimal process is 175.05 h, which is more than twice that of the specimen treated with “single step solution+low temperature first aging+secondary aging”.

Key words: recycled alloy of DD494 turbine blade, heat treatment, γ' precipitate phase, creep rupture mechanism

CLC Number:

TG113

Yang Shanjie, Hao Zhibo, Yuan Xiaofei. Heat treatment for recycled material of DD494 alloy turbine blade[J]. Heat Treatment of Metals, 2024, 49(6): 1-7.

References

[1]韩梅, 骆宇时. 改进DD3单晶高温合金热处理工艺的研究[J]. 航空材料学报, 2009, 29(2): 34-38.
Han Mei, Luo Yushi. Study of modified heat treatment for DD3 single crystal superalloys[J]. Journal of Aeronautical Materials, 2009, 29(2): 34-38.
[2]Caron P, Khan T. Evolution of Ni-based super alloys for single crystal gas turbine blade applications[J]. Aerospace Science and Technology, 1999, 3(8): 513-523.
[3]郭建亭. 高温合金材料学(中册)[M]. 北京: 科学出版社, 2008.
[4]师昌绪, 仲增墉. 中国高温合金五十年[M]. 北京: 冶金工业出版社, 2006.
[5]来永军, 宁礼奎, 柳一川, 等. 热处理对一种抗热腐蚀单晶高温合金组织和持久性能的影响[J]. 稀有金属材料与工程, 2023, 52(6): 2243-2252.
Lai Yongjun, Ning Likui, Liu Yichuan, et al. Effect of heat treatment on microstructures and stress rupture properties of hot-corrosion resistant single crystal superalloy[J]. Rare Metal Materials and Engineering, 2023, 52(6): 2243-2252.
[6]杜云玲. 镍基单晶高温合金热处理工艺与组织性能调控研究[D]. 合肥: 中国科学技术大学, 2022.
Du Yunling. Research on heat treatment process and structure and property control of nickel based single crystal high temperature alloy[D]. Beijing: University of Science and Technology of China, 2022.
[7]朱鸥, 李玉龙, 张燕, 等. 航空发动机用单晶铸造高温合金热处理工艺[J]. 铸造技术, 2013, 27(2): 1137-1140.
Zhu Ou, Li Yulong, Zhang Yan, et al. Heat treatment process for single-crystal superalloys used in aeroengines[J]. Casting Technology, 2013, 27(2): 1137-1140.
[8]杨雨轩, 王晔, 刘国怀, 等. 热处理过程中DD6单晶高温合金的组织演化规律与力学性能[J]. 金属热处理, 2022, 47(11): 1-11.
Yang Yuxuan, Wang Ye, Liu Guohuai, et al. Microstructure evolution and mechanical properties of DD6 single crystal superalloy during heat treatment process[J]. Heat Treatment of Metals, 2022, 47(11): 1-11.
[9]王欢, 宁礼奎, 佟健, 等. 两种热处理对镍基单晶高温合金CMSX-4微观组织和持久性能的影响[J]. 稀有金属材料与工程, 2020, 49(1): 247-256.
Wang Huan, Ning Likui, Tong Jian, et al. Effect of heat treatment on microstructures and stress rupture properties in the nickel base single crystal superalloy CMSX-4[J]. Rare Metal Materials and Engineering, 2020, 49(1): 247-256.
[10]Wilson B C, Fuchs G E. The effect of composition, misfit, and heat treatment on the primary creep behavior of single crystal nickel base super alloys PWA1480 and PWA1484[J]//Superalloys, 2008: 149-158.
[11]李志强, 黄朝晖, 谭永宁, 等. 表面再结晶对DD5镍基单晶高温合金组织和力学性能的影响[J]. 航空材料学报, 2011, 31(5): 1-5.
Li Zhiqiang, Huang Zhaohui, Tan Yongning, et al. Effect of surface recrystallization on microstructure and mechanical properties of nickel base single-crystal superalloy DD5[J]. Journal of Aeronautical Materials, 2011, 31(5): 1-5.
[12]Shi Z X, Li J R, Liu S Z. Effect of Hf on stress rupture properties of DD6 single crystal super alloy after long term aging[J]. Journal of Iron and Steel Research International, 2012, 19(7): 66-70.
[13]Kondo Y, Kitazaki N, Namekata J, et al. Effect of morphology of γ' phase on creep resistance of a single crystal nickel-based superalloy, CMSX-4[J]. Superalloys, 1996: 297-304.
[14]Harris K, Erickson G L, Sikkenga S L, et al. Development of the rhenium containing superalloys CMSX-4 and CM186LC for single crystal blade and directionally solidified vane applications in advanced turbine engines[J]. Superalloys, 1992: 297-306.
[15]胡壮麒, 刘丽荣, 金涛, 等. 镍基单晶高温合金的发展[J]. 航空发动机, 2005(3): 1-7.
Hu Zhuangqi, Liu Lirong, Jin Tao, et al. Development of the Ni-Based single crystal superalloy[J]. Aeroengine, 2005(3): 1-7.
[16]张静华, 张志亚, 李英敖. DD8单晶镍基高温合金热处理制度研究[J]. 材料开发与应用, 1997(1): 27-33.
Zhang Jinghua, Zhang Zhiya, Li Ying'ao. Investigation of the heat treatment in a single crystal nickel-base superalloy[J]. Development and Application of Materials, 1997(1): 27-33.
[17]袁晓飞, 吴剑涛, 李俊涛, 等. K424合金超温后的显微组织与典型性能[J]. 稀有金属材料与工程, 2018, 47(6): 1779-1785.
Yuan Xiaofei, Wu Jiantao, Li Juntao, et al. Microstructure and typical mechanical properties of overheated K424 superalloy[J]. Rare Metal Materials and Engineering, 2018, 47(6): 1779-1785.
[18]Véron M, Bréchet Y, Louchet F. Strain induced directional coarsening in Ni based super alloys[J]. Scripta Materialia, 1996, 34(12): 1883-1886.
[19]Osada T, Gu Y F, Nagashima N, et al. New quantitative analysis of contributing factors to strength of disk superalloys[J]//Superalloys, 2012: 121-128.
[20]喻健, 李嘉荣, 史振学, 等. DD6单晶高温合金二次γ'相的析出[J]. 稀有金属材料与工程, 2013, 42(8): 1654-1658.
Yu Jian, Li Jiarong, Shi Zhenxue, et al. Precipitation of secondary γ' phase of DD6 single crystal superalloy[J]. Rare Metal Materials and Engineering, 2013, 42(8): 1654-1658.
[21]Walston W S, Bernstein I M, Thompson A W. The role of the γ/γ' eutectic and porosity on the tensile behavior of a single-crystal nickel-base superalloy[J]. Metallurgical and Materials Transactions A, 1991, 22(6): 1443-1451.
[22]Qin X Z, Guo J T, Yuan C, et al. Decomposition of primary MC carbide and its effects on the fracture behaviors of a cast Ni-base super alloy[J]. Materials Science and Engineering A, 2008, 485(1/2): 74-79.