Abstract
An investigation was carried out to examine the influence of microstructure on the plane strain fracture toughness of austempered ductile iron. Austempered ductile iron (ADI) alloyed with nickel, copper, and molybdenum was austenitized and subsequently austempered over a range of temperatures to produce different microstructures. The microstructures were characterized through optical microscopy and X-ray diffraction. Plane strain fracture toughness of all these materials was determined and was correlated with the microstructure. The results of the present investigation indicate that the lower bainitic microstructure results in higher fracture toughness than upper bainitic microstructure. Both volume fraction of retained austenite and its carbon content influence the fracture toughness. The retained austenite content of 25 vol pct was found to provide the optimum fracture toughness. It was further concluded that the carbon content of the retained austenite should be as high as possible to improve fracture toughness.
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R.B. Gundalach and J.F. Janowak: Met. Progr., 1985, vol. 128 (2), pp. 19–26.
R.B. Gundalach and J.F. Janowak: AFS Trans., 1983, vol. 91, pp. 377–88.
R.A. Harding and G.N.J. Gilbert: Br. Foundryman, 1986, vol. 79, pp. 489–96.
I. Schmidt: Z. Metallkd., 1984, vol. 75, pp. 747–51.
S.M. Shah and J.D. Verhoeven: Wear, 1986, vol. 113, pp. 267–73.
I. Schmidt and A. Schuchert: Z. Metallkd., 1987, vol. 78, pp. 871–76.
I. Bartosiewicz, A.R. Krause, F. A. Alberts, I. Singh, and S.K. Putatunda: Mater. Charact., 1993, vol. 30, pp. 221–34.
P. Shanmugam, P.P. Rao, K.R. Udupa, and N. Venkataraman: J. Mater. Sci., 1994, vol. 29, pp. 4933–40.
G. Wilkinson and C. Grupke: Proc. 2nd Int. Conf. on Austempered Ductile Iron, Ann Arbor, MI, Mar. 1986, American Foundrymen’s Society, Des Plaines, IL, 1991, pp. 349–58.
J. Panasiewicz, C. Grupke, and J. Huth: Proc. World Conf. on Austempered Ductile Iron, Bloomingdale, IL, Mar. 1991, American Foundrymen’s Society, Des Plaines, IL, 1991, pp. 176–94.
K. Okazaki, H. Asai, M. Tokyoshi, H. Kusunoki, and H. Sakahara: Proc. World Conf. on Austempered Ductile Iron, Bloomingdale, IL, American Foundrymen’s Society, Des Plaines, IL, 1991, pp. 288–99.
E. Dorzail, B. Barta, E. Muntsorova, L. Stransky, and A. Huvar: AFS Int. Cast Met. J., 1982, vol. 7, pp. 52–58.
J. Janowak and R.B. Gundalach: AFS Trans, 1983, vol. 86, pp. 377–88.
T.N. Rouns, K.B. Rundman, and D.M. Moore: AFS Trans, 1984, vol. 92, pp. 815–40.
N. Darwish and R. Elliot: Mater. Sci. Technol., 1993, vol. 9, pp. 882–89.
K.H. Zum Gahr and L. Wagner: Arch. Eisenhuttenwes., 1979, vol. 50, pp. 269–74.
J.L. Doong, F.C. Ju, H.S. Chen, and L.W. Chen: J. Mater. Sci. Lett., 1986, vol. 5, pp. 555–58.
J.L. Doong and C.S. Chen: Fat. Fract. Eng. Mater. Struct., 1989, vol. 12, pp. 155–65.
L. Bartosiewicz, I. Singh, F.A. Alberts, A.R. Krause, and S.K. Putatunda: J. Mater. Eng. Perf., 1993, vol. 4, pp. 90–101.
S.K. Putatunda and I. Singh: J. Test. Eval., 1995, vol. 23, pp. 325–32.
M. Grech, P. Bowen, and J.M. Young: Proc. World Conf. on Austempered Ductile Iron, Bloomingdale, Il, American Foundrymen’s Society, Des Plaines, IL, Mar. 1991, pp. 338–74.
E. Dorazil and M. Holzman: Proc. World Conf. on Austempered Ductile Iron, Bloomingdale, IL, American Foundrymen’s Society, Des Plaines, IL, Mar, 1991, pp. 32–66.
J. Aranzabal, I. Gutierez, J.M. Rodriguez-Ibabe, and J.J. Urcola: Mater. Sci. Technol., 1992, vol. 8, pp. 263–73.
K.B. Rundman and R.C. Klug: AFS Trans., 1982, vol. 90, pp. 499–508.
C.S. Roberts: Trans. AIME, 1953, vol. 197, pp. 203–04.
B.D. Cullity: Elements of X-ray Diffraction, Addison-Wesley, Reading, MA, 1974, pp. 411–12.
Annual Book of ASTM Standards ASTM, Philadelphia, PA, 1992, vol. 03.01, p. 745.
Annual Book of ASTM Standards ASTM, Philadelphia, PA, 1992, vol. 03.01, p. 130.
R.C. Voigt and C.R. Loper: Proc. 1st Int. Conf. on Austempered Ductile Iron, ASM, Metals Park, OH, 1984, pp. 83–88.
M.D. VanMaldegiam and K.B. Rundman: AFS Trans., 1986, vol. 94, pp. 249–54.
D.J. Moore, T.N. Rouns, and K.B. Rundman: AFS Trans., 1987, vol. 95, pp. 765–74.
R. Voigt, H. Dhane, and L. Eldoky: Proc. 2nd Int. Conf. on Austempered Ductile Iron, Ann Arbor, MI, Gerared Research Institute, Naperville, IL, 1986, pp. 327–35.
P. Mayr, H. Vetters, and J. Walla: Proc. 2nd Int. Conf. on Austempered Ductile Iron, Ann Arbor, MI, Geared Research Institute, Naperville, IL, 1986, pp. 171–78.
J. Vuorinen: Proc. 2nd Int. Conf. on Austempered Ductile Iron, Ann Arbor, MI, Geared Research Institute, Naperville, IL, 1986, pp. 179–85.
R. Gundalach and J. Janowak: Proc. 2nd Int. Conf. on Austempered Ductile Iron, Ann Arbor, MI, Geared Research Institute, Naperville, IL, 1986, pp. 23–30.
R.C. Klug, M.B. Hintz, and K.B. Rundman: Metall. Trans. A, 1985, vol. 16A, pp. 797–805.
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Rao, P.P., Putatunda, S.K. Influence of microstructure on fracture toughness of austempered ductile iron. Metall Mater Trans A 28, 1457–1470 (1997). https://doi.org/10.1007/s11661-997-0208-1
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DOI: https://doi.org/10.1007/s11661-997-0208-1