Influence of long-term isothermal aging on microstructure and creep rupture properties of Ni-base superalloy M4706

Abstract

After a standard heat treatment, the microstructural evolution with time during isothermal aging at 850 °C and its effect on the creep rupture properties of the Ni-base superalloy M4706 at 870 °C and 370 MPa are investigated. It is found that as the aging time increases from 0 to 5000 h, the average diameter of coarse γ’ increases from 241 to 484 nm, and the distribution of the carbides at grain boundaries changes from discontinuous to continuous. Moreover, experimental observations on the microstructures of all the crept specimens reveal that dislocation bypassing controls the creep deformation. Thus, it is concluded that the transitions in the microstructures result in the degeneration of the creep rupture properties of the experimental alloy with aging time.

Keywords

Ni-base superalloy / isothermal aging / microstructure / creep rupture properties

References

[1] ReedR CThe superalloys fundamentals and applications [M], 2006, New York, Cambridge University Press

[2] PolockT M. Alloy design for aircraft engines [J]. Nature Materials, 2016, 15(8): 809-815

[3] ZhangP, YuanY, ShenS C, LiB, ZhuR H, YangG X, SongX L. Tensile deformation mechanisms at various temperatures in a new directionally solidified Ni-base superalloy [J]. Journal of Alloys and Compounds, 2017, 694: 502-509

[4] SajjadiS A, NateghS, GuthrieR I. Study of microstructure and mechanical properties of high performance Ni-base superalloy GTD-111 [J]. Materials Science and Engineering A, 2002, 325(1): 484-489

[5] ChuZ-k, YuJ-j, SunX-f, GuanH-r, HuZ-qi. High-temperature creep deformation and fracture behavior of a directionally solidified Ni-base superalloy DZ951 [J]. Metallurgical and Materials Transactions A, 2009, 40(12): 2927-2937

[6] HashizumeR, YoshiariA, KiyonoT, MurataY, MorinagaM. Development of novel Ni-based single crystal superalloys for power-generation gas turbines [J]. Materials at High Temperatures, 2007, 24(3): 163-172

[7] Van, SluytmanJ S, PollockT M. Optimal precipitate shapes in nickel-base γ-γ’ alloys [J]. Acta Materialia, 2012, 60(4): 1771-1783

[8] TianS-g, TianN, YuH-c, MengX-l, LiYing. Influence of solution temperature on microstructure and creep property of a directional solidified nickel-based superalloy at intermediate temperatures [J]. Materials Science and Engineering A, 2014, 615(7): 469-480

[9] LiuJ L, JinT, YuJ J, SunX F, GuanH, HuZ. Effect of thermal exposure on stress rupture properties of a Re bearing Ni base single crystal superalloy [J]. Materials Science and Engineering A, 2010, 527(4): 890-897

[10] QinX Z, GuoJ T, YuanC, ChenC L, YeH Q. Effects of long-term thermal exposure on the microstructure and properties of a cast Ni-base superalloy [J]. Metallurgical and Materials Transactions A, 2007, 38(12): 3014-3022

[11] JiangX W, WangD, XieG, LiH, LouL H, ZhangJ. The effect of long-term thermal exposure on the microstructure and stress rupture property of a directionally solidified ni-based superalloy [J]. Metallurgical and Materials Transactions A, 2014, 45(13): 6016-6026

[12] ZhangP, YuanY, LiJ, XuY F, SongX L, YangG X. Tensile deformation mechanisms in a new directionally solidified Ni-base superalloy containing coarse γ’ precipitates at 650 °C [J]. Materials Science and Engineering A, 2017, 702: 343-349

[13] YuanX F, SongJ X, ZhengY R, HuangQ, YagiK, XiaoC B, FengQ. Quantitative microstructural evolution and corresponding stress rupture property of K465 superalloy [J]. Materials Science and Engineering A, 2016, 651: 734-744

[14] YuanX F, SongJ X, ZhengY R, HuangQ, YagiK, XiaoC B, FengQ. Abnormal stress rupture property in K465 superalloy caused by microstructural degradation at 975 °C/225 MPa [J]. Journal of Alloys and Compounds, 2016, 662: 583-592

[15] WuJ, LiC, LiuY C, WuY, GuoQ, LiH, WangH. Effect of annealing treatment on microstructure evolution and creep behavior of a multiphase Ni3Al-based superalloy [J]. Materials Science and Engineering A, 2019, 743: 623-635

[16] ZhangP, YuanY, LiB, GuoS W, YangG X, SongX L. Tensile deformation behavior of a new Ni-base superalloy at room temperature [J]. Materials Science and Engineering A, 2016, 655: 152-159

[17] KozarR W, SuzukiA, MilliganW W, SchirraJ J, SavageM F, PollockT M. Strengthening mechanisms in polycrystalline multimodal nickel-base superalloys [J]. Metallurgical and Materials Transactions A, 2009, 40A(7): 1588-1603

[18] MartensV, NembachE. Strengthening of Nimonic alloy PE 16 by ordered particles of Ni3(Al, Ti) [J]. Acta Metallurgica, 1975, 23(2): 149-153

[19] HeilmaierM, LeetzU, ReppichB. Order strengthening in the cast nickel-based superalloy IN 100 at room temperature [J]. Materials Science and Engineering A, 2001, 319: 375-378

[20] ZhangP, YuanY, YanJ B, WangJ C, SongX L, YangG X. Morphological evolution of γ’ precipitates in superalloy M4706 during thermal aging [J]. Materials Letters, 2018, 211: 107-109

[21] WuY-t, LiuY-c, LiC, XiaX-c, WuJ, LiH-jun. Coarsening behavior of γ’ precipitates in the γ’+γ area of a Ni3Al-based alloy [J]. Journal of Alloys and Compounds, 2019, 771: 526-533

[22] LiuT, WangJ S, DongJ S, WangL, LouL H. Effect of heat treatment on microstructure and stress rupture properties of a Ni-Mo-Cr-Fe base corrosion-resistant superalloy [J]. Acta Metallurgical Sinica (English Letters), 2019, 32(1): 116-126

[23] LvovG, LevitV I, KaufmanM J. Mechanism of primary MC carbid. decomposition in Ni-base superalloys [J]. Metallurgical and Materials Transactions A, 2004, 35(6): 1669-1679

[24] WangJ, ZhouL, ShengL, GuoJ. The microstructure evolution and its effect on the mechanical properties of a hot-corrosion resistant Ni-based superalloy during long-term thermal exposure [J]. Materials and Design, 2012, 39: 55-62

[25] PollockT M, FieldR D. Dislocations and hightemperature plastic deformation of superalloy single crystals [J]. Dislocations in Solids, 2002, 11: 566-568

[26] CuiL-q, SuH-h, YuJ-j, LiuJ-l, JinT, SunX-feng. The creep deformation and fracture behaviors of nickel-base superalloy M951G at 900 °C [J]. Material Science and Engineering A, 2017, 707: 383-391

[27] NabarroF R N, VilliersH L DThe physics of creep [M], 1996, London, Taylor and Francis Press

[28] TianS-g, ZhangB-s, YuH-c, TianN, LiQ-yang. Microstructure evolution and creep behaviors of a directionally solidified nickel-base alloy under long-life service condition [J]. Materials Science and Engineering A, 2016, 673: 391-399

[29] BlumW, ReppichBCreep behaviour of crystalline solids [M], 1985, Swansea, Pineridge Press: 83135

[30] ArdellA JIntermetallics compounds as precipitates and dispersoids in high-strength alloys [M], 1995257286