The Feasibility and Process Control of Uniform Equiaxed Grains by Hot Deformation in GH4720Li Alloy with Millimeter-Level Coarse Grains

doi:10.11900/0412.1961.2020.00415

Acta Metall Sin

2021, Vol. 57

Issue (10): 1309-1319 DOI: 10.11900/0412.1961.2020.00415

Research paper

Current Issue | Archive | Adv Search

The Feasibility and Process Control of Uniform Equiaxed Grains by Hot Deformation in GH4720Li Alloy with Millimeter-Level Coarse Grains

LIU Chao, YAO Zhihao(

), JIANG He, DONG Jianxin

School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China

Cite this article:

LIU Chao, YAO Zhihao, JIANG He, DONG Jianxin. The Feasibility and Process Control of Uniform Equiaxed Grains by Hot Deformation in GH4720Li Alloy with Millimeter-Level Coarse Grains. Acta Metall Sin, 2021, 57(10): 1309-1319.

Download:

HTML

PDF(3699KB)
Export: BibTeX | EndNote (RIS)

Abstract

For nickel-based GH4720Li superalloys, fine-grained structures can be obtained via hot deformation in a two-phase area. However, obvious recrystallized grains' coarsening occurs because of the lack of prime γ' pinning grain boundary when hot deformation occurs in a single-phase area. Much attention is directed to the hot deformation of GH4720Li alloys with fine grains. Moreover, several studies have reported the hot deformation behavior of coarse-grained GH4720Li alloys, with maximum grain sizes of several hundred microns. However, only a few studies report about the hot deformation of GH4720Li alloy with millimeter-level coarse grains. Coarse grains recrystallize incompletely and can reduce the hot deformation plasticity of GH4720Li alloy. Thus, to clarify the coordination feasibility between recrystallization and the hot deformation plasticity of GH4720Li alloy with millimeter-level coarse grains, the hot deformation behavior of GH4720Li alloy with millimeter-level coarse grains was investigated under different deformation parameters (deformation temperature of 1130, 1160, and 1190°C; strain rates of 0.001, 0.01, 0.1, and 1 s^-1; and engineering strain of 50%) and compared with the hot deformation behavior of fine-grained GH4720Li alloy. The results show that the GH4720Li sample with millimeter-level coarse grains is more sensitive to the deformation temperature, but the fine-grained GH4720Li alloy is more sensitive to strain rate. The completely recrystallized structure of the GH4720Li sample with millimeter-level coarse grains can be obtained in the range of 1160-1190°C and 0.001-0.01 s^-1. However, a meager strain rate can cause an undesirable and obvious grain growth. After comprehensively combining the recrystallization control range and the hot deformation plasticity of millimeter-level coarse-grained GH4720Li alloy, it was found that the millimeter-level coarse-grained GH4720Li alloy should be thermally deformed at a moderate deformation temperature and a reduced strain rate of 1160^oC and 0.01 s^-1, respectively, to obtain the uniform equiaxed grains structure without cracking, and better deformation.

Key words: nickel-based superalloy GH4720Li alloy hot deformation recrystallization

Received: 23 October 2020

ZTFLH:

TG146.1

Fund: National Natural Science Foundation of China(51771016)

About author: YAO Zhihao, associate professor, Tel: 13671347055, E-mail: zhihaoyao@ustb.edu.cn

	Service

	E-mail this article
	Add to citation manager
	E-mail Alert
	RSS
	（）
	Articles by authors
	Chao LIU
	Zhihao YAO
	He JIANG
	Jianxin DONG

URL:

https://www.ams.org.cn/EN/10.11900/0412.1961.2020.00415 OR https://www.ams.org.cn/EN/Y2021/V57/I10/1309

Fig.1 SEM image of fine-grained GH4720Li alloy sample (a) and OM image of coarse-grained GH4720Li alloy sample (b)

Fig.2 True stress-strain curves of fine-grained (a, b) and coarse-grained (c, d) GH4720Li alloy samples under strain rates ( $ε ˙$ ) of 0.001 s^-1 (a, c) and 1 s^-1 (b, d)

Fig.3 Peak stresses of fine-grained samples (hollow symbols) and coarse-grained (solid symbols) GH4720Li alloy samples under different deformation parameters

Fig.4 Strain rate sensitivity factors (m) of fine-grained (a) and coarse-grained (b) GH4720Li alloy samples (σ_p—peak stress)

Fig.5 Influences of deformation temperature (T) on the hot deformation of fine-grained (a) and coarse-grained (b) GH4720Li alloy samples (α—material constant)

Fig.6 Recrystallization structures of fine-grained (a, b) and coarse-grained (c, d) GH4720Li alloy samples under $ε ˙$ = 0.001 s^-1(a, c) and $ε ˙$ = 1 s^-1 (b, d) at 1130^oC

Fig.7 Recrystallization structures of fine-grained (a, b) and coarse-grained (c, d) GH4720Li alloy samples under $ε ˙$ = 0.001 s^-1 (a, c) and $ε ˙$ = 1 s^-1 (b, d) at 1190^oC

Fig.8 Recrystallization structures of coarse-grained GH4720Li alloy samples under 1160^oC, 0.01 s^-1 (a) and 1160^oC, 0.1 s^-1 (b)

Fig.9 Recrystallization volume fraction (%) of coarse-grained GH4720Li alloy samples (Red indicates complete recrystallization and no obvious grain growth; blue indicates complete recrystallization but obvious grain growth)

Fig.10 Cracking degree diagrams of coarse-grained (a) and fine-grained (b) GH4720Li alloy (Insets show the macro-morphologies of coarse-grained and fine-grained GH4720Li alloy samples)

Fig.11 Microstructure around cracks of coarse-grained GH4720Li alloy samples deformed at 1190^oC and 0.01 s^-1

Fig.12 Hot deformation control range of fine-grained GH4720Li alloy samples (CRC—complete recrystallization and cracking, CRNC—complete recrystallization and no cracking; light green indicates obvious grain growth in CRNC area)

Fig.13 Hot deformation control range of coarse-grained GH4720Li alloy samples (URC—uncomplete recrystallization and cracking, URNC—uncomplete recrystallization and no cracking; light green indicates obvious grain growth in CRNC area)

Fig.14 Variation of hot deformation control range with the initial grain size (d) of GH4720Li alloy

1	Sims C T, Stolof N S, Hangel W. Superalloys Ⅱ [M]. New York: John Wiley & Sons, Inc., 1987: 8
2	Furrer D, Fecht H. Ni-based superalloys for turbine discs [J]. JOM, 1999, 51(1): 14
3	Bryant D J, Mclntosh G. The manufacture and evaluation of a large turbine disc in cast and wrought alloy 720Li [A]. Superalloys 1996 [C]. Pittsburgh, PA: The Minerals, Metals, & Materials Society, 1996: 713
4	Gu Y F, Cui C Y, Yuan Y, et al. Research progress in a high performance cast & wrought superalloy for turbine disc applications [J]. Acta Metall. Sin., 2015, 51: 1191
	谷月峰, 崔传勇, 袁勇等. 一种高性能航空涡轮盘用铸锻合金的研究进展 [J]. 金属学报, 2015, 51: 1191
5	Matsui T, Takizawa H, Kikuchi H, et al. The microstructure prediction of alloy720Li for turbine disk applications [A]. Superalloys 2000 [C]. Pittsburgh, PA: The Minerals, Metals, & Materials Society, 2000: 127
6	Yu Q Y. Study on the correlation between γ' phases, grain size and deformation parameters for GH4720Li alloy [D]. Beijing: University of Science and Technology Beijing, 2013
	于秋颖. GH4720Li合金γ'相、晶粒度和热加工参数关联性研究 [D]. 北京: 北京科技大学, 2013
7	Chang L T, Jin H, Sun W R. Solidification behavior of Ni-base superalloy Udimet 720Li [J]. J. Alloys Compd., 2015, 653: 266
8	Song X P, Li H Y, Gai J F, et al. The decomposition of metastable high temperature γ' precipitates in U720Li alloy [J]. Acta Metall. Sin., 2005, 41: 1233
	宋西平, 李红宇, 盖靖峰等. U720Li合金高温析出γ′相的失稳分解 [J]. 金属学报, 2005, 41: 1233
9	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
10	Yu Q Y, Yao Z H, Dong J X. Hot deformation behavior of uniform fine-grained GH4720Li alloy based on its processing map [J]. Int. J. Min. Met. Mater., 2016, 23: 83
11	Chen J Y, Dong J X, Zhang M C, et al. Deformation mechanisms in a fine-grained Udimet 720Li nickel-base superalloy with high volume fractions of γ' phases [J]. Mater. Sci. Eng., 2016, A673: 122
12	Chen J Y, Zhang P D, Dong J X, et al. Relevance of primary γ' dissolution and abnormal grain growth in Udimet 720Li [J]. Mater. Trans., 2015, 56: 1968
13	Monajati H, Taheri A K, Jahazi M, et al. Deformation characteristics of isothermally forged Udimet 720 nickel-base superalloy [J]. Metall. Mater. Trans., 2005, 36A: 895
14	Liu F F, Chen J Y, Dong J X, et al. The hot deformation behaviors of coarse, fine and mixed grain for Udimet 720Li superalloy [J]. Mater. Sci. Eng., 2016, A651: 102
15	Wan Z P, Hu L X, Sun Y, et al. Hot deformation behavior and processing workability of a Ni-based alloy [J]. J. Alloys Compd., 2018, 769: 367
16	Wang T, Wan Z P, Sun Y, et al. Dynamic softening behavior and microstructure evolution of nickel base superalloy [J]. Acta Metall. Sin., 2018, 54: 83
	王涛, 万志鹏, 孙宇等. 镍基变形高温合金动态软化行为与组织演变规律研究 [J]. 金属学报, 2018, 54: 83
17	Zhao Y X, Fu S H, Zhang S W, et al. An advanced cast/wrought technology for GH720Li alloy disk from fine grain ingot [A]. 7th International Symposium on Superalloy 718 and Derivatives [C]. Pittsburgh, PA: The Minerals, Metals, & Materials Society, 2010: 271
18	Fahrmann M, Suzuki A. Effect of cooling rate on gleeble hot ductility of Udimet alloy 720 billet [A]. Superalloys 2008 [C]. Pittsburgh, PA: The Minerals, Metals, & Materials Society, 2008: 311
19	Wan Z P, Wang T, Sun Y, et al. Dynamic softening mechanisms of GH4720Li alloy during hot deformation [J]. Acta Metall. Sin., 2019, 55: 213
	万志鹏, 王涛, 孙宇等. GH4720Li合金热变形过程动态软化机制 [J]. Acta Metall. Sin., 2019, 55: 213
20	Qu J L, Bi Z N, Du J H, et al. Hot deformation behavior of nickel-based superalloy GH4720Li [J]. J. Iron Steel Res. Int., 2011, 18: 59
21	Preuss M, de Fonseca J Q, Grant B, et al. The effect of γ' particle size on the deformation mechanism in an advanced polycrystalline nickel-base superalloy [A]. Superalloys 2008 [C]. Pittsburgh, PA: The Minerals, Metals, & Materials Society, 2008: 405
22	Xie B C, Ning Y Q, Zhou C. Deformation behavior and microstructure evolution of two typical structures in Udimet 720Li ingot [J]. Proc. Eng., 2017, 207: 1093
23	Wang T, Wan Z P, Li Z, et al. Effect of heat treatment parameters on microstructure and hot workability of as-cast fine grain ingot of GH4720Li alloy [J]. Acta Metall. Sin., 2020, 56: 182
	王涛, 万志鹏, 李钊等. 热处理工艺对GH4720Li合金细晶铸锭组织与热加工性能的影响 [J]. 金属学报, 2020, 56: 182
24	Hyzak J M, Singh R P, Morra J, et al. The microstructural response of as-hip P/M U-720 to thermomechanical processing [A]. Superalloys 1992 [C]. Pittsburgh, PA: The Minerals, Metals, & Materials Society, 1992: 93
25	Monajati H, Zarandi F, Jahazi M, et al. Strain induced γ' precipitation in nickel base superalloy Udimet 720 using a stress relaxation based technique [J]. Scr. Mater., 2005, 52: 771
26	Pang H T, Hardy M C, Hide N, et al. Comparison of fatigue crack propagation in nickel base superalloys RR1000 and Udimet 720Li [J]. Mater. Sci. Technol., 2016, 32: 22
27	Wang X Q, Peng Z C, Zhang M C. Hot deformation behavior of AA-FGH720Li superalloy [J]. Mater. Sci. Forum, 2017, 898: 528
28	Bozzolo N, Souaï N, Logé R E. Evolution of microstructure and twin density during thermomechanical processing in a γ-γ' nickel-based superalloy [J]. Acta Mater., 2012, 60: 5056
29	Yu Q Y, Yao Z H, Dong J X. Deformation and recrystallization behavior of a coarse-grain, nickel-base superalloy Udimet720Li ingot material [J]. Mater. Charact., 2015, 107: 398

[1]	ZHAO Peng, XIE Guang, DUAN Huichao, ZHANG Jian, DU Kui. Recrystallization During Thermo-Mechanical Fatigue of Two High-Generation Ni-Based Single Crystal Superalloys[J]. 金属学报, 2023, 59(9): 1221-1229.
[2]	WANG Lei, LIU Mengya, LIU Yang, SONG Xiu, MENG Fanqiang. Research Progress on Surface Impact Strengthening Mechanisms and Application of Nickel-Based Superalloys[J]. 金属学报, 2023, 59(9): 1173-1189.
[3]	JIANG He, NAI Qiliang, XU Chao, ZHAO Xiao, YAO Zhihao, DONG Jianxin. Sensitive Temperature and Reason of Rapid Fatigue Crack Propagation in Nickel-Based Superalloy[J]. 金属学报, 2023, 59(9): 1190-1200.
[4]	CHANG Songtao, ZHANG Fang, SHA Yuhui, ZUO Liang. Recrystallization Texture Competition Mediated by Segregation Element in Body-Centered Cubic Metals[J]. 金属学报, 2023, 59(8): 1065-1074.
[5]	YUAN Jianghuai, WANG Zhenyu, MA Guanshui, ZHOU Guangxue, CHENG Xiaoying, WANG Aiying. Effect of Phase-Structure Evolution on Mechanical Properties of Cr₂AlC Coating[J]. 金属学报, 2023, 59(7): 961-968.
[6]	LI Fulin, FU Rui, BAI Yunrui, MENG Lingchao, TAN Haibing, ZHONG Yan, TIAN Wei, DU Jinhui, TIAN Zhiling. Effects of Initial Grain Size and Strengthening Phase on Thermal Deformation and Recrystallization Behavior of GH4096 Superalloy[J]. 金属学报, 2023, 59(7): 855-870.
[7]	LOU Feng, LIU Ke, LIU Jinxue, DONG Hanwu, LI Shubo, DU Wenbo. Microstructures and Formability of the As-Rolled Mg- xZn-0.5Er Alloy Sheets at Room Temperature[J]. 金属学报, 2023, 59(11): 1439-1447.
[8]	YU Shaoxia, WANG Qi, DENG Xiangtao, WANG Zhaodong. Preparation and Size Effect of GH3600 Nickel-Based Superalloy Ultra-Thin Strips[J]. 金属学报, 2023, 59(10): 1365-1375.
[9]	ZHU Guoliang, KONG Decheng, ZHOU Wenzhe, HE Jian, DONG Anping, SHU Da, SUN Baode. Research Progress on the Crack Formation Mechanism and Cracking-Free Design of γ' Phase Strengthened Nickel-Based Superalloys Fabricated by Selective Laser Melting[J]. 金属学报, 2023, 59(1): 16-30.
[10]	WU Caihong, FENG Di, ZANG Qianhao, FAN Shichun, ZHANG Hao, LEE Yunsoo. Microstructure Evolution and Recrystallization Behavior During Hot Deformation of Spray Formed AlSiCuMg Alloy[J]. 金属学报, 2022, 58(7): 932-942.
[11]	SUN Yi, ZHENG Qinyuan, HU Baojia, WANG Ping, ZHENG Chengwu, LI Dianzhong. Mechanism of Dynamic Strain-Induced Ferrite Transformation in a 3Mn-0.2C Medium Mn Steel[J]. 金属学报, 2022, 58(5): 649-659.
[12]	YANG Qinzheng, YANG Xiaoguang, HUANG Weiqing, SHI Duoqi. Propagation Behaviors of Small Cracks in Powder Metallurgy Nickel-Based Superalloy FGH4096[J]. 金属学报, 2022, 58(5): 683-694.
[13]	REN Shaofei, ZHANG Jianyang, ZHANG Xinfang, SUN Mingyue, XU Bin, CUI Chuanyong. Evolution of Interfacial Microstructure of Ni-Co Base Superalloy During Plastic Deformation Bonding and Its Bonding Mechanism[J]. 金属学报, 2022, 58(2): 129-140.
[14]	JIANG Weining, WU Xiaolong, YANG Ping, GU Xinfu, XIE Qingge. Formation of Dynamic Recrystallization Zone and Characteristics of Shear Texture in Surface Layer of Hot-Rolled Silicon Steel[J]. 金属学报, 2022, 58(12): 1545-1556.
[15]	HU Chen, PAN Shuai, HUANG Mingxin. Strong and Tough Heterogeneous TWIP Steel Fabricated by Warm Rolling[J]. 金属学报, 2022, 58(11): 1519-1526.

No Suggested Reading articles found!

Viewed

Full text

Abstract

Cited

Shared

Discussed