Abstract
In this study, the effects of initial microstructure on the flow stress, strain rate sensitivity (m), and microstructure during hot deformation of GH4720LI alloy with different initial microstructures were studied using hot compression tests over a wide temperatures range of 1080–1180 °C and strain rates (0.001–10 s−1) to a final true strain of 0.8. The results showed that flow stress and deformation mechanisms of the alloys were significantly affected by the γ′ precipitates. The flow stresses of the two initial microstructures (i.e., microstructures AC and AF) presented typical DRX softening behavior and exhibited nearly a consistent variation trend which was decreased with the increase of temperature. The peak stresses in the microstructure of as-forged samples with smaller initial grain size were lower than microstructure AC when deformation temperature was lower than 1160 °C. While the gap between the two sets of specimens gradually decreased over a temperature of 1160 °C, which was mainly attributed to dissolution of the γ′ precipitates in alloys. According to the analysis of the strain rate sensitivity values distribution maps with two initial microstructures, the deformation mechanisms of the alloys in various deformation conditions were discussed in detail. Dislocation glide/climb was identified as the dominant deformation mechanism at low temperature, while grain boundary sliding and accommodation was confirmed as the main deformation mechanism at high temperature 1180 °C and low strain rate.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
K. Gopinath, A.K. Gogia, S.V. Kamat et al., Dynamic strain ageing in Ni-base superalloy 720Li. Acta Mater. 57(4), 1243–1253 (2009)
M.P. Jackson, R.C. Reed, Heat treatment of UDIMET 720Li: the effect of microstructure on properties. Mater. Sci. Eng., A 259(1), 85–97 (1999)
Y.S. Na, N.K. Park, R.C. Reed, Sigma morphology and precipitation mechanism in UDIMET 720Li. Scripta Mater. 43(7), 585–590 (2000)
H.M. Wang, P.D. Wu, S. Kurukuri et al., Strain rate sensitivities of deformation mechanisms in magnesium alloys. Int. J. Plast. 107, 207–222 (2018)
R. Radis, M. Schaffer, M. Albu et al., Multimodal size distributions of γ′ precipitates during continuous cooling of UDIMET 720Li. Acta Mater. 57(19), 5739–5747 (2009)
Z.P. Wan, L.X. Hu, Y. Sun et al., Microstructure evolution and dynamic softening mechanisms during high-temperature deformation of a precipitate hardening Ni-based superalloy. Vacuum 155, 585–593 (2018)
Y. Nan, Y.Q. Ning, H.Q. Liang et al., Work-hardening effect and strain-rate sensitivity behavior during hot deformation of Ti–5Al–5Mo–5V–1Cr–1Fe alloy. Mater. Des. 82, 84–90 (2015)
P. Lin, Y.G. Hao, B.Y. Zhang et al., Strain rate sensitivity of Ti–22Al–25Nb (at%) alloy during high temperature deformation. Mater. Sci. Eng., A 710, 336–342 (2018)
A. Bintu, G. Vincze, C.R. Picu et al., Strain hardening rate sensitivity and strain rate sensitivity in TWIP steels. Mater. Sci. Eng., A 629, 54–59 (2015)
Q. Zuo, F. Liu, L. Wang et al., Prediction of hot deformation behavior in Ni-based alloy considering the effect of initial microstructure. Prog. Nat. Sci.: Mater. Int. 25(1), 66–77 (2015)
P. Gao, M. Zhan, X. Fan et al., Hot deformation behavior and microstructure evolution of TA15 titanium alloy with nonuniform microstructure. Mater. Sci. Eng., A 689, 243–251 (2017)
F.F. Liu, J.Y. Chen, J.X. Dong et al., The hot deformation behaviors of coarse, fine and mixed grain for UDIMET 720Li superalloy. Mater. Sci. Eng., A 651, 102–115 (2016)
L. Li, M.Q. Li, J. Luo, Flow softening mechanism of Ti–5Al–2Sn–2Zr–4Mo–4Cr with different initial microstructures at elevated temperature deformation. Mater. Sci. Eng., A 628, 11–20 (2015)
Z.X. Zhang, S.J. Qu, A.H. Feng et al., Hot deformation behavior of Ti–6Al–4V alloy: effect of initial microstructure. J. Alloy. Compd. 718, 170–181 (2017)
Z.H. Jiang, P. Wang, D.Z. Li et al., The evolutions of microstructure and mechanical properties of 2.25Cr–1Mo–0.25V steel with different initial microstructures during tempering. Mater. Sci. Eng., A 699, 165–175 (2017)
F. Pilehva, A. Zarei-Hanzaki, S.M. Fatemi-Varzaneh, The influence of initial microstructure and temperature on the deformation behavior of AZ91 magnesium alloy. Mater. Des. 42, 411–417 (2012)
F.L. Li, R. Fu, F.J. Yin et al., Impact of γ′(Ni3(Al, Ti)) phase on dynamic recrystallization of a Ni-based disk superalloy during isothermal compression. J. Alloy. Compd. 693, 1076–1082 (2017)
I.J. Moore, J.I. Taylor, M.W. Tracy et al., Grain coarsening behaviour of solution annealed Alloy 625 between 600–800 °C. Mater. Sci. Eng., A 682, 402–409 (2017)
P. Zhang, Y. Yuan, J. Li et al., Tensile deformation mechanisms in a new directionally solidified Ni-base superalloy containing coarse γ′ precipitates at 650 °C. Mater. Sci. Eng., A 702, 343–349 (2017)
J.X. Dong, L.H. Li, H.N. Li et al., Effect of extent of homogenization on the hot deformation recrystallization of superalloy ingot in cogging process. Acta Metall. Sin. 51(10), 1207–1218 (2015)
A. Belyakov, H. Miura, T. Sakai, Dynamic recrystallization in ultra fine-grained 304 stainless steel. Scripta Mater. 43(1), 21–26 (2000)
M. El Wahabi, L. Gavard, F. Montheillet et al., Effect of initial grain size on dynamic recrystallization in high purity austenitic stainless steels. Acta Mater. 53(17), 4605–4612 (2005)
W.Z. Wang, H.U. Hong, I.S. Kim et al., Influence of γ′ and grain boundary carbide on tensile fracture behaviors of Nimonic 263. Mater. Sci. Eng., A 523(1), 242–245 (2009)
C. Joseph, C. Persson, M. Hörnqvist Colliander, Influence of heat treatment on the microstructure and tensile properties of Ni-base superalloy Haynes 282. Mater. Sci. Eng., A 679, 520–530 (2017)
L.W. Yang, C.Y. Wang, M.A. Monclús et al., Influence of temperature on the strain rate sensitivity and deformation mechanisms of nanotwinned Cu. Scripta Mater. 154, 54–59 (2018)
K. Li, V.S.Y. Injeti, R.D.K. Misra et al., On the strain rate sensitivity of aluminum-containing transformation-induced plasticity steels: Interplay between TRIP and TWIP effects. Mater. Sci. Eng., A 711, 515–523 (2018)
J. Gao, M.Q. Li, G.J. Liu et al., Deformation behavior and processing maps during isothermal compression of TC21 alloy. Rare Met. 36(2), 86–94 (2017)
F.L. Li, R. Fu, D. Feng et al., Hot workability characteristics of Rene88DT superalloy with directionally solidified microstructure. Rare Met. 34(1), 51–63 (2015)
F.C. Liu, T.W. Nelson, Grain structure evolution, grain boundary sliding and material flow resistance in friction welding of Alloy 718. Mater. Sci. Eng., A 710, 280–288 (2018)
D. Peter, G.B. Viswanathan, M.F.X. Wagner et al., Grain-boundary sliding in a TiAl alloy with fine-grained duplex microstructure during 750 °C creep. Mater. Sci. Eng., A 510–511, 359–363 (2009)
M.A. Meyers, K.K. Chawla, Mechanical Behavior of Materials (Cambridge University Press, New York, 2009)
E.V. Boltynjuk, D.V. Gunderov, E.V. Ubyivovk et al., Enhanced strain rate sensitivity of Zr-based bulk metallic glasses subjected to high pressure torsion. J. Alloy. Compd. 747, 595–602 (2018)
W.J. Kim, J. Wolfenstine, O.D. Sherby, Tensile ductility of superplastic ceramics and metallic alloys. Acta Metall. Mater. 39(2), 199–208 (1991)
Acknowledgements
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2019 Springer Nature Singapore Pte Ltd.
About this paper
Cite this paper
Wan, ZP. et al. (2019). Strain Rate Sensitivity of GH4720LI Alloy with Two Initial Microstructures During Hot Deformation. In: Han, Y. (eds) Physics and Engineering of Metallic Materials. CMC 2018. Springer Proceedings in Physics, vol 217. Springer, Singapore. https://doi.org/10.1007/978-981-13-5944-6_27
Download citation
DOI: https://doi.org/10.1007/978-981-13-5944-6_27
Published:
Publisher Name: Springer, Singapore
Print ISBN: 978-981-13-5943-9
Online ISBN: 978-981-13-5944-6
eBook Packages: Physics and AstronomyPhysics and Astronomy (R0)