Hot deformation behavior and micro-structure evolution of superalloy GH742
ZHANG Beijiang; ZHAO Guangpu; XU Guohua; FENG Di
High Temperature Materials Division; Central Iron and Steel Research Institute
Cite this article:
ZHANG Beijiang; ZHAO Guangpu; XU Guohua; FENG Di. Hot deformation behavior and micro-structure evolution of superalloy GH742. Acta Metall Sin, 2005, 41(11): 1207-1214 .
Abstract Hot deformation behavior of superalloy GH742 was studied by isothermal compression test conducted on MTS machine. Flow stress data at various temperatures from 950℃ to 1150℃ and strain rates from 0.001 s-1 to 1 s-1 were obtained, microstructure evolution during deformation under the above conditions was also investigated. The results show that when deformation was performed at single phase region above 1075℃, rather low flow stress is exhibited, the apparent activation energy approachs the activation energy of grain boundary diffusion, the deformation mechanism is controlled by grain growth rate and the fully recrystallized structures can be achieved. In two phase region, GH742 alloy presents considerably high activation energy, with decreasing temperature and increasing strain rate the flow stress increases swiftly, while the dynamic recrystallization was strongly prohibited. At transition temperature between single and two phase regions, a discontinuous change in flow stress was observed, and the apparent activation energy sharply increased, strain induced dynamically precipitated γ phase inhibits the migration of grain boundaries, the diameter of the recrystallized grain is drastically reduced with increase of plastic strain, and the microstructure was effectively refined.
[1] Long Z D, Zhuang J Y, Deng B, Zhong Z Y. Acta Metall Sin, 1999; 35: 1211 (龙正东,庄景云,邓波,仲增墉．金属学报,1999;35:1211) [2] Meyers M A, Benson D J, Vohringer O, Kad B K, Xue Q,Fu H H. Mater Sci Eng, 2002; A322: 194 [3] Semiatin S L, Weaver D S, Fagin P N, Glavicic M G. Metall Mater Trans, 2004; 35A: 679 [4] Hayes R W. Acta Metall, 1983; 31: 365 [5] Doherty R D, Hughes D A, Humphreys F J, Jonas J J.Mater Sci Eng, 1997; A238: 219 [6] Prasad Y, Seshacharyulu T. Int Mater Rev, 1998; 43: 243 [7] Shen G S, Semiatin S L, Shivpuri R. Metall Mater Trans,1995; 26A: 1795 [8] Verdier M, Brechet Y, Guyot P. Acta Mater, 1999; 47:127 [9] Sakai T, Ohashi M, Jonas J J. Acta Metall, 1988; 36: 1781 [10] Verdier M, Brechet Y, Guyot P. Acta Mater, 1999; 47:127 [11] Speer J G, Hasen S S. Metall Trans, 1989; 20A: 25 [12] Simmons J P, Wen Y, Shen C, Wang Y Z. Mater Sci Eng,2004; A365: 136 [13] Gourdet S, Montheillet F. Acta Mater, 2003; 51: 2685 [14] Song X Y, Markus R, Zhang J X. Acta Metall Sin, 2004; 40: 1009 (宋晓艳,Markus R,张久兴．金属学报,2004;40:1009) [15] McQueen H J, Ryan N D. Mater Sci Eng, 2002; A322: 43 [16] Weertman J. J Appl Phys, 1957; 28: 362 [17] Bruni C, Forcellese A, Gabrielli F. Mater Sci Technol,2002; 125: 242 [18] Siddall R J, Eggar J W. Mater Sci Technol, 1986; 2: 728 [19] Wahabi M E, Cabrera J M, Prado J M. Mater Sci Eng,2003; A343: 116 [20] Briottet L, Jonas J J, Monthellet F. Acta Mater, 1996;44:1665 [21] Gottstein G, Kocts U. Acta Metall, 1983; 31: 175 [22] Sakai T, Jonas J J. Acta Metall, 1984; 32: 189 [23] Crespo D, Pradell T, Clavaguera N. Mater Sci Eng, 1997;A238: 160 [24] Kazaryan A, Wang Y, Dregia S A, Patton B R. Acta Mater, 2002; 50: 2491 [25] Tian B, Wang Y, Zickler G A, Lind C, Paris O. Acta Mater, 2003; 51: 4149
