Evolution of Microstructure and Mechanical Properties of FGH4720Li P/M Superalloy Under Near-Service Conditions
Received date: 2023-04-25
Revised date: 2023-07-17
Online published: 2023-11-01
Supported by
National Natural Science Foundation of China(52271087);National Science and Technology Major Project(J2017-VI-0017-089)
The FGH4720Li superalloy is produced by GH4720Li through the powder metallurgy (P/M) process, a method that effectively addresses the shortcomings of the original alloy production process, such as significant segregation, low alloying levels, and manufacturing difficulties. The P/M method also results in a finer and more uniform microstructure. However, during the service life of superalloys, the thermodynamic conditions can degrade the microstructure, potentially affecting their mechanical properties. There is currently limited research on how the microstructure and properties of FGH4720Li P/M superalloy evolve under near-service conditions. Therefore, it is essential to investigate this evolution to provide valuable insights for the manufacture of turbine disks. In this study, the microstructure evolution of FGH4720Li P/M superalloy and the variations in its yield strength have been examined after subjecting it to stress rupture for 500, 1000, and 2000 h at 600 and 650 oC under a stress level of 500 MPa. The results show that the yield strength of FGH4720Li P/M superalloy remains relatively high, at 1120 MPa, after stress rupture at 650 oC. Furthermore, the microstructure of FGH4720Li P/M superalloy undergoes a complex transformation during stress rupture. The secondary γ' phase's morphology gradually changes from an ellipsoidal shape to a flowerlike shape and ultimately to a cubic shape with rounded corners. The coarsening in the polymerization growth of tertiary γ' phases is also observed. To understand the changes in yield strength after stress rupture, a precipitation strengthening prediction model specifically designed for high γ' phase content and a multi-mode distribution of γ' phases was utilized. This calculation confirmed that the alteration in the content and size of the tertiary γ' phase is the primary factor responsible for the yield strength changes in the alloy.
LI Dayu , YAO Zhihao , ZHAO Jie , DONG Jianxin , GUO Jing , ZHAO Yu . Evolution of Microstructure and Mechanical Properties of FGH4720Li P/M Superalloy Under Near-Service Conditions[J]. Acta Metall Sin, 2025 , 61(6) : 826 -836 . DOI: 10.11900/0412.1961.2023.00188
| 1 | Yang J J, Zhang C S, Li H J, et al. Effect of tension-torsion coupled loading on the mechanical properties and deformation mechanism of GH4169 superalloys [J]. Acta Metall. Sin., 2024, 60: 30 |
| 杨俊杰, 张昌盛, 李洪佳 等. 拉伸-扭转复合加载对镍基高温合金GH4169力学性能与变形机理的影响 [J]. 金属学报, 2024, 60: 30 | |
| 2 | Li F L, Bai Y R, Meng L C, et al. Impact of aging heat treatment on microstructure and mechanical properties of a newly developed GH4096 disk superalloy [J]. Mater. Charact., 2020, 161: 110175 |
| 3 | Locq D, Caron P. On some advanced nickel-based superalloys for disk applications [J]. Aerosp. Lab, 2011, 3: 1 |
| 4 | Azadi M, Marbout A, Safarloo S, et al. Effects of solutioning and ageing treatments on properties of Inconel-713C nickel-based superalloy under creep loading [J]. Mater. Sci. Eng., 2018, A711: 195 |
| 5 | Jiang X W, Wang D, Xie G, et al. The effect of long-term thermal exposure on the microstructure and stress rupture property of a directionally solidified Ni-based superalloy [J]. Metall. Mater. Trans., 2014, 45A: 6016 |
| 6 | Jackson M P, Reed R C. Heat treatment of UDIMET 720Li: The effect of microstructure on properties [J]. Mater. Sci. Eng., 1999, A259: 85 |
| 7 | Tan L M, Li Y P, Deng W K, et al. Tensile properties of three newly developed Ni-base powder metallurgy superalloys [J]. J. Alloys Compd., 2019, 804: 322 |
| 8 | Deng W K, Zhang D, Wu H Y, et al. Prediction of yield strength in a polycrystalline nickel base superalloy during interrupt cooling [J]. Scr. Mater., 2020, 183: 139 |
| 9 | Yao Z H, Hou J, Chen Y, et al. Effect of micron-sized particles on the crack growth behavior of a Ni-based powder metallurgy superalloy [J]. Mater. Sci. Eng., 2022, A860: 144242 |
| 10 | Radis R, Schaffer M, Albu M, et al. Multimodal size distributions of γ′ precipitates during continuous cooling of UDIMET 720 Li [J]. Acta Mater., 2009, 57: 5739 |
| 11 | Wan Z P, Hu L X, Sun Y, et al. Effect of solution treatment on microstructure and tensile properties of a U720LI Ni-based superalloy [J]. Vacuum, 2018, 156: 248 |
| 12 | Mao J, Chang K M, Yang W H, et al. Cooling precipitation and strengthening study in powder metallurgy superalloy U720LI [J]. Metall. Mater. Trans., 2001, 32A: 2441 |
| 13 | Huang Z L, Xie X F, Gu Y, et al. Tensile properties of Ni-based GH4720Li superalloys with different microstructures at 650 oC [J]. Chin. J. Rare Met., 2021, 45: 1269 |
| 黄子琳, 谢兴飞, 谷 雨 等. GH4720Li镍基合金显微组织对650 ℃拉伸性能影响 [J]. 稀有金属, 2021, 45: 1269 | |
| 14 | Yuan Y, Gu Y F, Cui C Y, et al. Creep mechanisms of U720Li disc superalloy at intermediate temperature [J]. Mater. Sci. Eng., 2011, A528: 5106 |
| 15 | Terzi S, Couturier R, Guétaz L, et al. Modelling the plastic deformation during high-temperature creep of a powder-metallurgy coarse-grained superalloy [J]. Mater. Sci. Eng., 2008, A483-484: 598 |
| 16 | Zhao G D, Zang X M, Jing Y, et al. Role of carbides on hot deformation behavior and dynamic recrystallization of hard-deformed superalloy U720Li [J]. Mater. Sci. Eng., 2021, A815: 141293 |
| 17 | Wang T, Li Z, Fu S H, et al. Hot deformation behavior and microstructure of U720Li alloy [J]. Adv. Mater. Res., 2013, 709: 143 |
| 18 | Pang H T, Reed P A S. Microstructure effects on high temperature fatigue crack initiation and short crack growth in turbine disc nickel-base superalloy Udimet 720Li [J]. Mater. Sci. Eng., 2007, A448: 67 |
| 19 | Tucker A M, Henderson M B, Wilkinson A J, et al. High temperature fatigue crack growth in powder processed nickel based superalloy U720Li [J]. Mater. Sci. Technol., 2002, 18: 349 |
| 20 | Liu C, Yao Z H, Jiang H, et al. The feasibility and process control of uniform equiaxed grains by hot deformation in GH4720Li alloy with millimeter-level coarse grains [J]. Acta Metall. Sin., 2021, 57: 1309 |
| 刘 超, 姚志浩, 江 河 等. GH4720Li合金毫米级粗大晶粒热变形获得均匀等轴晶粒的可行性及工艺控制 [J]. 金属学报, 2021, 57: 1309 | |
| 21 | Liu C, Yao Z H, Guo J, et al. Microstructure evolution behavior of powder superalloy FGH4720Li at near service temperature [J]. Acta Metall. Sin., 2021, 57: 1549 |
| 刘 超, 姚志浩, 郭 婧 等. 粉末高温合金FGH4720Li在近服役温度下的组织演变规律 [J]. 金属学报, 2021, 57: 1549 | |
| 22 | Li M Z, Coakley J, Isheim D, et al. Influence of the initial cooling rate from γ′ supersolvus temperatures on microstructure and phase compositions in a nickel superalloy [J]. J. Alloys Compd., 2018, 732: 765 |
| 23 | Hu B F, Liu G Q, Wu K, et al. Morphological instability of γ′ phase in nickel-based powder metallurgy superalloys [J]. Acta Metall. Sin., 2012, 48: 257 |
| 胡本芙, 刘国权, 吴 凯 等. 镍基粉末冶金高温合金中γ′相形态不稳定性研究 [J]. 金属学报, 2012, 48: 257 | |
| 24 | Kong W W, Wang Y Q, Yuan C, et al. Microstructural evolution and stress rupture behaviour of a Ni-Based wrought superalloy during thermal exposure [J]. Mater. Sci. Eng., 2021, A822: 141659 |
| 25 | Schulz F, Li H Y, Kitaguchi H, et al. Influence of tertiary gamma prime (γ′) size evolution on dwell fatigue crack growth behavior in CG RR1000 [J]. Metall. Mater. Trans., 2018, 49A: 3874 |
| 26 | Raynor D, Silcock J M. Strengthening mechanisms in γ′ precipitating alloys [J]. Met. Sci. J., 1970, 4: 121 |
| 27 | Dang C X, Zhang P, Li J, et al. The role of <112> {111} slip in the initial plastic deformation of Ni-base superalloys at room temperature [J]. Mater. Charact., 2020, 170: 110648 |
| 28 | Zhang P, Yuan Y, Li B, et al. Tensile deformation behavior of a new Ni-base superalloy at room temperature [J]. Mater. Sci. Eng., 2016, A655: 152 |
| 29 | Goodfellow A J. Strengthening mechanisms in polycrystalline nickel-based superalloys [J]. Mater. Sci. Technol., 2018, 34: 1793 |
| 30 | Kozar R W, Suzuki A, Milligan W W, et al. Strengthening mechanisms in polycrystalline multimodal nickel-base superalloys [J]. Metall. Mater. Trans., 2019, 40A: 1588 |
| 31 | Nembach E, Neite G. Precipitation hardening of superalloys by ordered γ′-particles [J]. Prog. Mater. Sci., 1985, 29: 177 |
| 32 | Zhao C L, Wang Q, Tang Y, et al. Microstructure and property stability of powder metallurgy nickel-based U720Li superalloy during long-term aging [J]. Rare Met. Mater. Eng., 2022, 51: 2356 |
| 33 | Yao Z H, Dong J X, Chen X, et al. Gamma prime phase evolution during long-time exposure for GH738 superalloy [J]. Trans. Mater. Heat Treat., 2013, 34(1): 31 |
| 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 | |
| 34 | Torster F, Baumeister G, Albrecht J, et al. Influence of grain size and heat treatment on the microstructure and mechanical properties of the nickel-base superalloy U 720 LI [J]. Mater. Sci. Eng., 1997, A234: 189 |
| 35 | Xu Y L, Jin Q M, Xiao X S, et al. Strengthening mechanisms of carbon in modified nickel-based superalloy Nimonic 80A [J]. Mater. Sci. Eng., 2011, A528: 4600 |
| 36 | Huang H L, Liu G Q, Wang H, et al. Effect of cooling rate and resulting microstructure on tensile properties and deformation mechanisms of an advanced PM nickel-based superalloy [J]. J. Alloys Compd., 2019, 805: 1254 |
| 37 | Osada T, Nagashima N, Gu Y, et al. Factors contributing to the strength of a polycrystalline nickel-cobalt base superalloy [J]. Scr. Mater., 2011, 64: 892 |
| 38 | Galindo-Nava E I, Connor L D, Rae C M F. On the prediction of the yield stress of unimodal and multimodal γ′ nickel-base superalloys [J]. Acta Mater., 2015, 98: 377 |
| 39 | Gerold V, Haberkorn H. On the critical resolved shear stress of solid solutions containing coherent precipitates [J]. Phys. Status Solidi, 1966, 16B: 675 |
| 40 | Ahmadi M R, Povoden-Karadeniz E, Whitmore L, et al. Yield strength prediction in Ni-base alloy 718Plus based on thermo-kinetic precipitation simulation [J]. Mater. Sci. Eng., 2014, A608: 114 |
| 41 | Kocks U F, Mecking H. Physics and phenomenology of strain hardening: The FCC case [J]. Prog. Mater. Sci., 2003, 48: 171 |
| 42 | Zhang H K, Li Y, Ma T F, et al. Tailoring of nanoscale γ′ precipitates and unveiling their strengthening mechanisms in multimodal nickel-based superalloy GH4720Li [J]. Mater. Charact., 2022, 188: 111918 |
| 43 | Labusch R. A statistical theory of solid solution hardening [J]. Phys. Status Solidi, 1970, 41B: 659 |
| 44 | Gypen L A, Deruyttere A. Multi-component solid solution hardening: part 2 Agreement with experimental results [J]. J. Mater. Sci., 1977, 12: 1034 |
| 45 | Reppich B, Schepp P, Wehner G. Some new aspects concerning particle hardening mechanisms in γ′ precipitating nickel-base alloys—II. Experiments [J]. Acta Metall., 1982, 30: 95 |
/
| 〈 |
|
〉 |
