Effect of Mixed Grain Structure on High Temperature Stress Rupture Propertyof Ni-based GH4720Li Superalloy
XIE Xingfei1,2, QU Jinglong1,2, DU Jinhui1,2
1 Beijing GAONA Materials & Technology Co., LTD, Beijing 100081, China; 2 High Temperature Materials Research Institute, Central Iron and Steel Research Institute, Beijing 100081, China
Abstract: GH4720Li nickel-based superalloy has excellent high temperature mechanical properties, and has been widely used in hot end components of aero-engine. In the actual production process, it is easy to obtain the mixed crystal structure with local coarse grains in GH4720Li superalloy. In this paper, effect of mixed grains structure in GH4720Li superalloy on rupture property at 680 ℃/830 MPa and 730 ℃/530 MPa was studied through high temperature stress rupture tests and scanning electron microscope. The results indicate that rupture failure mechanism is dominated by the dislocation movement within grains at 680 ℃/830 MPa, and the rupture life decreases with increase of the number of coarse grains. The grain boundary slip mechanism also plays a role when the content of coarse grains in the mixed grains is the similar, and increasing the size of coarse grains can effectively prolong rupture life. Moreover, the rupture failure mechanism at 730 ℃/530 MPa is dominated by grain boundary slip mechanism, and the rupture life is prolonged as increase of the number of coarse grains. For the similar content of coarse grain in mixed grain structure, the rupture life decreases with increase of coarse grain size.
1 Pang H T, Reed P A S. International Journal of Fatigue,2008,30(10),2009. 2 Monajati H, Taheri A K, Jahazi M, et al. Metallurgical & Materials Transactions A,2005,36(4),895. 3 Chen J Y, Dong J X, Zhang M C, et al. Materials Science & Engineering A,2016,673(15),122. 4 Qu J L, Xie X F, Bi Z N, et al. Journal of Alloys and Compounds,2019,785(15),918. 5 曲敬龙,杜金辉,毕中南,等.钢铁研究学报,2012,24(2),48. 6 Qu J L, Bi Z N, Du J H, et al. Journal of Iron and Steel Research International,2011,18(10),59. 7 于秋颖,张麦仓,董建新.北京科技大学学报,2013,35(6),763. 8 Billot T, Villechaise P, Jouiad M, et al. International Journal of Fatigue,2010,32(5),824. 9 Song X, Tang L, Chen Z, et al. Journal of Materials Science,2017,52,4587. 10 Agh A, Amini A. International Journal of Minerals, Metallurgy and Materials,2018,25(9),1035. 11 Phan V T, Zhang X, Li Y, et al. Mechanics of Materials,2017,114,215. 12 Thébaud L, Villechaise P, Crozet C, et al. Mateials Science and Engineering A,2018,716,274.13 Cui L, Yu J, Liu J, et al.Mateials Science and Engineering A,2018,710,309. 14 Murakumo T, Kobayashi T, Koizumi Y, et al. Acta Materialia,2004,52,3737. 15 Yao Z H, Zhang M C, Dong J X. Metallurgical and Materials Transactions A,2013,44,3084. 16 朱丽娜,李文,祁峰,等.热加工工艺,2011,40(16),47. 17 Smith T M, Rao Y, Wang Y, et al.Acta Materialia,2017,141,261.
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2020, Vol. 34 
