Thermodynamic calculation and experimental analysis of precipitated phase of Nimonic 80A alloy

doi:10.13251/j.issn.0254-6051.2024.12.025

Abstract

Abstract: Variation of equilibrium phases with temperature of Nimonic 80A alloy with different element contents was calculated by Thermo-Calc thermodynamic simulation software, and the effects of main elements on the types of precipitates, precipitation temperature and precipitation content were analyzed. In order to verify the reliability of thermodynamic calculation, the microstructure characteristics, qualitative and quantitative analysis of aged alloy samples were carried out by means of SEM, TEM, XRD and so on. The results show that the equilibrium precipitates of Nimonic 80A alloy are γ, γ', M₂₃C₆, MX and M₇C₃ phases. Decreasing C content cannot only increase the precipitation temperature of M₇C₃ phase, but also promote the precipitation amount of γ'phase; increasing the content of Al and Ti increases the precipitation temperature of M₇C₃, γ' and M₂₃C₆ phases, and promotes the precipitation of γ'and M₂₃C₆ phase, in which the effect of single Al element is higher than that of Ti element; increasing the total content of Ti+Al increases the precipitation temperatures of M₂₃C₆ and γ' phases, and the precipitation content of γ' phase increases significantly. With the increase of Ti/Al ratio, the precipitation content of γ' phase decreases gradually. Under 1060 ℃×8 h air cooling, 845 ℃×24 h air cooling and 700 ℃×16 h air cooling double aging process, a large number of M₇C₃, M₂₃C₆ and γ' phases are precipitated. The γ' phases of different sizes strengthened the precipitation strengthening of the alloy, and the carbides strengthened the grain boundary strengthening of the alloy. Within the prescribed range of alloy composition, the lower limit of C content(0.05%-0.075%), the middle limit of Al content(1.3%-1.6%) and the upper limit of Ti content(2.3%-2.7%) were selected. The upper limit of the total amount of Ti+Al(3.65%-4.46%) and the middle limit of the specific content of Ti/Al(1.76) can obtain a good distribution ratio of precipitated phase.

Key words: Nimonic 80A alloy, equilibrium precipitated phase, Thermo-Calc calculation, precipitation strengthening, aging process

CLC Number:

TG166.7

Wang Yunhai, Xin Ruishan, Gong Zhihua, Zhao Jiqing, Yang Gang, Bao Hansheng. Thermodynamic calculation and experimental analysis of precipitated phase of Nimonic 80A alloy[J]. Heat Treatment of Metals, 2024, 49(12): 148-156.

References

[1]吴明华, GH4080A镍基合金材料[P]. 中国: CN109985926A, 2022-02-24.
[2]张立红. GH80A合金相的溶解析出规律及热处理制度研究[J]. 热处理, 2003(3): 26-30.
Zhang Lihong. Study onrule of solution and precipitation of phases and method for heat treatment of GH80A alloy[J]. Heat Treatment, 2003(3): 26-30.
[3]汤咏舫, 刘勇, 张芳. 两次时效GH80A合金的组织特征[J]. 金属热处理, 2000(5): 11-13.
Tang Yongfang, Liu Yong, Zhang Fang. Microstructure characteristic of GH80A alloy treated with two aging process[J]. Heat Treatment of Metals, 2000(5): 11-13.
[4]何马飞. GH80A和GH105合金长时组织稳定性的研究[D]. 北京: 中国农业大学, 2002.
He Mafei. Study on the long time structural stability of GH80A and GH105 superalloys[D]. Beijing: China Agricultural University, 2002.
[5]Wilthan B, Tanzer R, Schützenhfer W, et al. Thermophysical properties of the Ni-based alloy Nimonic 80A up to 2400 K[J]. Rare Metals, 2006(5): 529-531.
[6]Zhang H, Li Z, Fruchart D, et al. Crystal structure analysis of oxide film of new zirconium alloys[J]. Rare Metal Materials and Engineering, 2006, 35(12): 1908-1911.
[7]Jiao S Y, Zhang M C, Zheng L, et al. Investigation of carbide precipitation process and chromium depletion during thermal treatment of alloy 690[J]. Metallurgical and Materials Transactions A, 2010, 41: 26-42.
[8]赵义瀚. 超超临界汽轮机耐热钢设计及析出物研究[D]. 哈尔滨: 哈尔滨工程大学, 2012.
Zhao Yihan. Design and precipitates of supercritical steam turbines heat-resistant steel[D]. Harbin: Harbin University of Engineering, 2012.
[9]Ge Tingting, Dong Jianxin, Zhang Maicang. Microstructure characteristics of GH80A superalloy and thermodynamic calculation on precipitated phases[J]. Rare Metal Materials and Engineering, 2011, 40(7): 1178-1183.
[10]徐敏, 杨武强, 张斌, 等. 镍基高温合金GH141平衡析出相的热力学计算分析[J]. 稀有金属材料与工程, 2016, 45(11): 2925-2931.
Xu Min, Yang Wuqiang, Zhang Bin, et al. Thermodynamic calculation and analysis of GH141 equilibrium precipitates in Ni-base superalloy[J]. Rare Metal Materials and Engineering, 2016, 45(11): 2925-2931.
[11]徐裕来. 超超临界汽轮机叶片用高温合金Nimonic 80A成分优化、微结构及其高温强化机理研究[D]. 上海: 上海大学, 2013.
Xu Yulai. Study on composition optimization, microstructure and high temperature strengthening mechanism of superalloy Nimonic 80A for ultra-supercritical steam turbine blades[D]. Shanghai: Shanghai University, 2013.
[12]刘帅, 吕知清, 赵吉庆, 等. 2Cr12Ni4Mo3VNbN钢中析出相的热力学计算与试验分析[J]. 钢铁, 2022, 57(5): 129-136.
Liu Shuai, Lü Zhiqing, Zhao Jiqing, et al. Thermodynamic calculation and experimental analysis on equilibrium precipitation phase in 2Cr12Ni4Mo3VNbN steel[J]. Iron and Steel, 2022, 57(5): 129-136.
[13]丁雅莉, 苏杰, 陈嘉砚, 等. S-04马氏体时效不锈钢析出相的热力学计算及强化工艺的优化[J]. 钢铁研究学报, 2003(6): 38-41.
Ding Yali, Su Jie, Chen Jiayan, et al. Thermodynamic calculation of precipitates and optimization of strengthening technology of maraging stainless steel S-04[J]. Journal of Iron and Steel Research, 2003(6): 38-41.
[14]李奇, 秦鹤勇, 郭翠萍, 等. 镍基高温合金GH4706析出相的热力学计算与分析[J]. 钢铁研究学报, 2017, 29(3): 208-215.
Li Qi, Qin Heyong, Guo Cuiping, et al. Thermodynamic calculation and theoretical analysis of equilibrium precipitation phases in Ni-based superalloy GH4706[J]. Journal of Iron and Steel Research, 2017, 29(3): 208-215.
[15]郑建军. 基于Thermo-Calc软件对V、Nb钢的热力学计算及V、Nb交互作用的分析[D]. 鞍山: 辽宁科技大学, 2012.
Zheng Jianjun. Thermodynamic calculation of V, Nb steel and analysis of the interaction of V, Nb based ontheThermo-Calc software[D]. Anshan: Liaoning University of Science and Technology, 2012.
[16]陈昱伶. 热处理制度对GH80A合金微观组织和力学性能的影响[D]. 重庆: 重庆大学, 2020.
Chen Yulin. Effect of heat treatment on microstructure and mechanical properties of GH80A alloys[D]. Chongqing: Chongqing University, 2020.
[17]于秋颖, 董建新, 张麦仓, 等. 热处理制度对超超临界电站用GH80A合金组织和性能的影响[J]. 稀有金属材料与工程, 2013, 42(7): 1507-1512.
Yu Qiuying, Dong Jianxin, Zhang Maicang, et al. Influence of heat treatments on microstructures and properties of GH80A superalloy for buckets of USC steam turbines[J]. Rare Metal Materials and Engineering, 2013, 42(7): 1507-1512.
[18]Liu L R, Jin T, Zhao N R, et al. Effect of carbon additions on the microstructure in a Ni-base single crystalsuperalloy[J]. Materials Letters, 2004, 58(17-18): 2290-2294.
[19]Wei C N, Bor H Y, Chang L. The effects of carbon content on the microstructure and elevated temperature tensile strength of a nickel-base superalloy[J]. Materials Science and Engineering A, 2010, 527(16/17): 3741-3747.
[20]Long F, Yoo Y S, Jo C Y, et al. Hu. Formation of η and σ phase in three polycrystalline superalloys andtheir impact on tensile properties[J]. Materials Science and Engineering A, 2009, 527(1/2): 361-369.
[21]王桂权. 基于Thermo-Calc多元多相合金微观偏析及凝固路径数值计算[D]. 哈尔滨: 哈尔滨工业大学, 2010.
Wang Guiquan. Thermocalc-based numerical simulation of the microsegregation and the solidification paths of multicomponent alloys[D]. Harbin: Harbin Institute of Technology, 2010.
[22]吕知清, 肖少彬, 吴之博, 等. 溶质元素晶界偏聚行为的研究现状[J]. 燕山大学学报, 2019, 43(6): 471-510.
Lü Zhiqing, Xiao Shaobin, Wu Zhibo, et al. Research status of segregation behaviors of solute atoms on grain boundary[J]. Journal of Yanshan University, 2019, 43(6): 471-510.
[23]高亚伟, 董建新, 姚志浩, 等. GH5188高温合金组织特征及冷热加工过程组织演变[J]. 稀有金属材料与工程, 2017, 46(10): 2922-2928.
Gao Yawei, Dong Jianxin, Yao Zhihao, et al. Microstructure characteristics and microstructure evolution during hot and cold working process of GH5188 super alloy[J]. Rare Metal Materials and Engineering, 2017, 46(10): 2922-2928.