Abstract
Alloy 625 ammonia cracker tubes were service exposed for 60,000 hours at 873 K. These were then subjected to a solution-annealing treatment at 1473 K for 0.5 hours. The effects of temperature and strain rate on the tensile properties of the solution-annealed alloy were examined in the temperature range of 300 to 1023 K, employing the strain rates in the range of 3×10−5 s−1 to 3×10−3 s−1. At intermediate temperatures (523 to 923 K), various manifestations of dynamic strain aging (DSA) such as serrated flow, peaks, and plateaus in the variations of yield strength (YS) and ultimate tensile strength (UTS) and work-hardening rate with temperature were observed. The activation energy for serrated flow (Q) was determined by employing various methodologies for T<823 K, where a normal Portevien-Le Chatelier effect (PLE) was observed. The value of Q was found to be independent of the method employed. The average Q value of 98 kJ/mol was found to be in agreement with that for Mo migration in a Ni matrix. At elevated temperatures (T≥823 K), type-C serrations and an inverse PLE was noticed. The decrease in uniform elongation beyond 873 K for 3×10−5 s−1 and 3×10−3 s−1 and beyond 923 K for 3×10−4 s−1 strain rates seen in this alloy has been ascribed to reduction in ductility due to precipitation of carbides and δ phase on the grain boundaries.
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E.E. Brown and D.R. Muzyka: in The Superalloys II, C.T. Sims and W.C. Hagel, eds., John Wiley, New York, NY, 1987, p. 165.
M. Sundararaman, Lalit Kumar, G.E. Prasad, P. Mukhopadhyay, and S. Banerjee: Metall. Mater. Trans. A, 1999, vol. 30A, p. 41.
H. Bohm, K. Ehlrich, and K.H. Krammer: Metallurgy, 1970, vol. 24, p. 643.
F. Garzarotli, A. Gerscha, and F.P. Francke: Z. Metallkd., 1969, vol. 60, p. 643.
S. Floreen, G.E. Fuchs, and W.J. Yang: in Superalloys 718, 625, 706 and Various Derivatives, E.A. Loria, ed., TMS, Warrendale, PA, 1994, p. 13.
M. Sundararaman, P. Mukhopadhyay, and S. Banerjee: Metall. Trans. A, 1988, vol. 19A, pp. 453–65.
M. Sundararaman, P. Mukhopadhyay, and S. Banerjee: Mater. Sci. Forum, 1985, vol. 3, p. 273.
I. Kirman: J. Iron Steel Inst., 1969, vol. 207, p. 1612.
Vani Shankar, K. Bhanu Sankara Rao, and S.L. Mannan: J. Nucl. Mater., 2001, vol. 288, pp. 222–32.
Vani Shankar, M. Valsan, K. Bhanu Sankara Rao, and S.L. Mannan: Scripta mater., 2001, vol. 44, pp. 2703–11.
L.Y. Popov and V.F. Sukharov: Phys. Met. Metallogr., 1964, vol. 17 (3), p. 100.
R. Summerling and J. Nutting: J. Iron Steel Inst., 1965, vol. 203, p. 398.
B.J. Brindley and P.J. Worthington: Met. Rev., 1970, vol. 145, p. 101.
J.D. Baird: Met. Rev., 1971, vol. 16, p. 1.
P. Rodriguez: Encyclopedia of Materials Science and Engineering—Supplement: R.W. Cahn, ed., Pergamon, 1988, vol. 1, pp. 504–08.
L.H. de Almeida and P.R.O. Emygdio: Scripta Metall. Mater., 1994, vol. 31 (5), pp. 505–10.
P.G. McCormick: Acta Metall., 1972, vol. 20, p. 351.
P. Rodriguez: Bull. Mater. Sci., 1984, vol. 6, p. 653.
K.W. Qian and R.E. Reed-Hill: Acta Metall., 1983, vol. 31, p. 87.
K. Mukherjee, C. Dantonio, R. Maciag, and G. Fischer: J. Appl. Phys., 1968, vol. 39, p. 5434.
I.S. Kim and M. Chaturvedi: Trans. Jpn. Inst. Met., 1987, vol. 28 (3), pp. 205–12.
E. Pink and A. Grinberg: Acta Metall., 1982, vol. 30, p. 2153.
B. Russell: Phil. Mag., 1963, vol. 8, p. 615.
Aerospace Structural Metals Handbook, Mechanical Properties Data Center, A DOD Materials information Center, Battelle Columbus Laboratories, Columbus, OH, 1982, vol. 4, code 4117, p. 24.
Superalloys 718, 625, 706 and Various Derivatives, E.A. Loria, ed., TMS, Warrendale, PA, 1994.
V.V. Raman, G.E. Prasad, and P. Das Gupta: Trans. Ind. Inst. Met., 1987, vol. 40, p. 113.
J.T. Barnby: J. Iron Steel Inst., 1965, vol. 203, p. 392.
D.J. Michel, J. Moteff, and A.J. Lovell: Acta Metall., 1973, vol. 21, p. 1269.
V. Kutumba Rao, D.M.R. Taplin, and P. Rama Rao: Metall. Trans. A, 1975, vol. 6A, pp. 77–86.
S.L. Mannan and P. Rodriguez: Trans. Ind. Inst. Met., 1983, vol. 36, p. 313.
S. Venkatesan, S. Venugopal, M. Vasudevan, and P.V. Sivaprasad: Mater. Sci. Technol., 1993, vol. 9, pp. 1–7.
K. Bhanu Sankara Rao, V. Seetharaman, S.L. Mannan, and P. Rodriguez: High Temp. Mater. Processes, 1986, vol. 7 (1), pp. 63–81.
D.R. Muzyka: in The Superalloys 718, C.T. Sims and W.C. Hagel, eds., Wiley, New York, NY, 1972, p. 113.
H.W. Tawancy, R.B. Herchenrocder, and A.J. Asphanani: J. Met., 1983, vol. 35, p. 37.
H.W. Tawancy: Metall. Trans. A, 1980, vol. 11A, pp. 1784–85.
M. Kumar and V.K. Vasudevan: Acta Mater., 1996, vol. 44, p. 1591.
Anish Kumar, Vani Shankar, T. Jayakumar, K. Bhanu Sankara Rao, and Baldev Raj: Phil. Mag. A, 2002, vol. 82 (13), p. 2529.
B. Ahlblom and R. Sandstrom: Int. Metall. Rev., 1982, vol. 27, pp. 1–27.
C.C. Koch and A.R. Troiano: Trans. ASM, 1964, vol. 57, p. 519.
L.H. De Almeida and S.N. Monteiro: 2nd Int. Conf. on Mechanical Behavior of Materials, ASM, Metals Park, OH, 1976, p. 1697.
R.A. Swalin: Acta Metall., 1957, vol. 5, p. 443.
J. Friedel: Dislocations, Pergamon, Oxford, UK, 1964, p. 102.
W. Charnock: Phil. Mag., 1969, vol. 20, p. 427.
A. Korbel, J. Zasadzinski, and Z. Sieklucka: Acta Metall., 1976, vol. 24, p. 919.
R.W. Hayes: Acta Metall., 1983, vol. 31, p. 365.
R.W. Hayes and W.C. Hayes: Acta Metall., 1984, vol. 32, p. 259.
S. Venkadesan, C. Phaniraj, P.V. Sivaprasad, and P. Rodriguez: Acta Metall., 1992, vol. 40, p. 569.
A.K. Koul and F.B. Pickering: Scripta Metall., 1982, vol. 16, p. 119.
C.F. Jenkins and G.V. Smith: Trans AIME, 1969, vol. 245, p. 2149.
H. Doi and Y. Shimanuki: Proc. 2nd Int. Conf. on Superalloys—Processing, Champion, PA, 1972, Metals and Ceramics Information Centre, Columbus, OH, 1972, p. 0–1.
C. Thomas and P. Tait: Int. J. Pressure Vessels Piping, 1994, 59.
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Shankar, V., Valsan, M., Rao, K.B.S. et al. Effects of temperature and strain rate on tensile properties and activation energy for dynamic strain aging in alloy 625. Metall Mater Trans A 35, 3129–3139 (2004). https://doi.org/10.1007/s11661-004-0057-0
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DOI: https://doi.org/10.1007/s11661-004-0057-0