Effect of aging treatment on microstructure and mechanical properties of high quality GH738 alloy

doi:10.13251/j.issn.0254-6051.2021.12.003

Abstract

Abstract: Effect of aging temperature and time on microstructure and properties of high quality GH738 alloy was studied by means of mechanical testing and microstructure observation. The results show that the aging temperature and time both affect the fraction and size of γ′ phase. When the aging temperature is between 720 ℃ and 800 ℃, with the increase of aging temperature, the strength of the alloy decreases, the primary and secondary γ′ phases grow up by 30 nm and 8 nm, respectively. The volume fraction of the primary γ′ phase increases, and that of the secondary γ′ phase decreases. When the aging temperature is 800 ℃, the volume fraction of the primary γ′ phase reaches the peak value as about 8%. When the aging time is between 0 and 48 h, with the increase of aging time, the alloy strength first increases and then decreases. The two types of γ′ phase grow up by 20 nm and 6 nm, respectively. The volume fraction of the primary γ′ phase increases first and then decreases, and that of the secondary γ′ phase just changes as the opposite. When the aging time is 8 h, the volume fractions of two types of γ′ phase reach their peak/valley values respectively, as about 8% and 12%. The changes in the size and volume fraction of the γ′ phase, especially volume fraction, lead to different effects of two strengthening mechanisms of dislocations, resulting in change in strength.

Key words: high quality GH738 alloy, aging treatment, γ′ phase, microstructure, mechanical properties

CLC Number:

TG132.3

Wu Yubo, Yang Chengbin, Hou Weixue, Rong Yi, Li Chun, Lu Yunjie, Li Lingli. Effect of aging treatment on microstructure and mechanical properties of high quality GH738 alloy[J]. Heat Treatment of Metals, 2021, 46(12): 13-18.

References

[1]荣义, 成磊, 唐超, 等. 固溶冷却介质对优质GH738合金组织及力学性能的影响[J]. 钢铁研究学报, 2016, 28(11): 74-78.
Rong Yi, Cheng Lei, Tang Chao, et al. Effects of cooling rate mediums for solution treatment on the microstructure and mechanical properties of high quality GH738 alloy[J]. Journal of Iron and Steel Research, 2016, 28(11): 74-78.
[2]陈国良, 谢锡善, 孟庆麟, 等. 高温合金学[M]. 北京: 冶金工业出版社, 1988.
[3]曲敬龙, 史玉亭, 荣义, 等. 优质GH738合金高温均匀化处理工艺研究[C]//第十四届中国高温合金年会论文集. 北京: 中国金属学会高温材料分会, 2019: 274-277.
[4]曲敬龙, 谷雨, 陈正阳, 等. 不同开坯工艺对优质GH738合金中夹杂物分布的影响[C]//第十四届中国高温合金年会论文集. 北京: 中国金属学会高温材料分会, 2019: 278-281.
[5]荣义, 张麦仓, 杨成斌, 等. 优质GH738合金热变形过程中的再结晶机制[J]. 钢铁研究学报, 2021, 33(6): 530-538.
Rong Yi, Zhang Maicang, Yang Chengbin, et al. Recrystallization mechanism of high quality GH738 alloy during hot deformation[J]. Journal of Iron and Steel Research, 2021, 33(6): 530-538.
[6]唐超, 于凯, 罗俊鹏, 等. GH4738合金断口附近的组织特征与持久寿命的关联性研究[J]. 热加工工艺, 2021, 50(14): 62-67.
Tang Chao, Yu Kai, Luo Junpeng, et al. Investigation on relationship between microstructure characteristic near fracture and creep rupture life for GH4738 alloy[J]. Hot Working Technology, 2021, 50(14): 62-67.
[7]曲敬龙, 荣义, 张麦仓, 等. 固溶温度对优质GH4738合金组织及力学性能的影响[C]//第十三届中国高温合金年会论文集. 北京: 中国金属学会高温材料分会, 2015: 154-158.
[8]李钢, 荣义, 杨成斌, 等. 稳定化处理对优质GH738合金组织及力学性能的影响[J]. 材料热处理学报, 2021, 42(7): 65-71.
Li Gang, Rong Yi, Yang Chengbin, et al. Effect of stabilizing treatment on microstructure and mechanical properties of high quality GH738 alloy[J]. Transactions of Materials and Heat Treatment, 2021, 42(7): 65-71.
[9]姚志浩, 董建新, 陈旭, 等. GH738高温合金长期时效过程中γ′相演变规律[J]. 材料热处理学报, 2013, 34(1): 31-37.
Yao Zhihao, Dong Jianxin, Chen Xu, et al. Gamma prime phase evolution during long-time exposure for GH738 superalloy[J]. Transactions of Materials and Heat Treatment, 2013, 34(1): 31-37.
[10]赵双群, 谢锡善. WASPALOY合金长期时效过程中的组织演变和性能变化[J]. 机械工程材料, 2006(10): 62-65.
Zhao Shuanqun, Xie Xishan. Mechanical properties and microstructure evolution of WASPALOY after long exposure[J]. Materials for Mechanical Engineering, 2006(10): 62-65.
[11]杨德庄. 位错与金属强化机制[M]. 哈尔滨: 哈尔滨工业大学出版社, 1991.
[12]Murphy H J, Sims C T, Hecheman G R. Long-time structures and properties of three high-strength nickel-base alloys[J]. Transactions of the Metallurgical Society of AIME, 1967, 239: 1961-1978.
[13]Decker R F. Strengthening mechanisms in nickel-base superalloys[C]//Steel Strengthening Mechanisms Symposium. Zurich: Climax Molybdenum Company, 1969: 1-24.
[14]Wessman A, Laurence A, Cormier J, et al. Thermal stability of cast and wrought alloy Rene 65[C]//13th International Symposium on Superalloys. Seven Springs, 2016: 793-800.
[15]袁晓飞, 丁贤飞, 八木晃一, 等. GH4098合金短时持久性能的研究[J]. 稀有金属材料与工程, 2015, 44(10): 2419-2428.
Yuan Xiaofei, Ding Xianfei, Yagi Koichi, et al. Short time stress rupture property in GH4098 alloy[J]. Rare Metal Materials and Engineering, 2015, 44(10): 2419-2428.