Abstract
A 0.06 pct C-0.3 pct Mn and a 0.07 pct C-0.6 pct Mn-0.028 pct Nb steel were deformed in torsion at a constant strain rate of 2/s. Two schedules were used. In schedule A, seven roughing passes executed between 1260°C and 1130°C were followed by a single large finishing pass with a strain of 3.5 at constant temperatures between 1010°C and 840°C. The time between roughing and finishing was 200 seconds. In schedule B, the seven roughing passes were followed by 10 finishing passes, again applied isothermally, with strains of 0.3 and interpass times of 0.6, 2, and 10 seconds. The results indicate that for the Nb steel, low rolling temperatures (870°C) and strains above 2 are required for complete dynamic recrystallization, which results in austenite grain sizes under 6μm. Cooled at a rate of 10°C/s, the dynamically recrystallized austenite grain structures transform into ferrite with grain sizes under 4 μ. Extrapolations from the present data suggest that at industrial strain rates and cooling rates, ferrite grain sizes under 2 μm should be achieved.
Similar content being viewed by others
References
T. Tanaka, N. Tabata, T. Hatomura, and C. Shiga: inMicro Alloying '75, Union Carbide Corporation, Indianapolis, IN, pp. 107–18.
H. Sekine, T. Maruyama, H. Kageyama, and Y. Kawashima: inThermomechanical Processing of Microalloyed Austenite, A.J. DeArdo, G.A. Ratz, and P.J. Wray, eds. TMS-AIME, Warrendale, PA, 1982, pp. 141–61.
F.H. Samuel, S. Yue, J.J. Jonas, and B.A. Zbinden:Iron Steel Inst. Jpn. Int., 1989, vol. 29, pp. 878–86.
F.H. Samuel, S. Yue, J.J. Jonas, and K.R. Barnes:Iron Steel Inst. Jpn. Int., 1990, vol. 30, pp. 216–25.
L.N. Pussegoda, S. Yue, and J.J. Jonas:Metall. Trans. A, 1990, vol. 21A, pp. 153–64.
T. Sakai, and J.J. Jonas:Acta Metall., 1984, vol. 32, pp. 189–209.
T. Chandra, S. Yue, and J.J. Jonas: in4th Int. Steel Rolling Conf., IRSID, Deauville, France, 1987, vol. 2, pp. F.181-F18.8
G.F. Vander Voort:Metallography, Principles and Practice, McGraw-Hill, New York, NY, 1984.
ASTM Specification E112-88, in1990 Annual Book of ASTM Standards, ASTM, Philadelphia, PA, 1990, vol. 03.01, pp. 282–306.
W.J. Liu, and J.J. Jonas:Metall. Trans. A, 1988, vol. 19A, pp. 1415–24.
C.M. Sellars, and W.J.McG. Tegart:Int. Metall. Rev., 1972, vol. 17, pp. 1–24.
W. Roberts: inDeformation, Processing, and Structure, G. Krauss, ed., ASM, Metals Park, OH, 1984, pp. 109–84.
A. Laasraoui: Ph.D. Thesis, McGill University, Montréal, 1990, pp. 124–25.
C.M. Sellars: inProcessing and Properties of Low Carbon Steels, J.M. Gray, ed., AIME, New York, NY, 1973, pp. 3–15.
T. Maki, K. Akasaka, and I. Tamura: inThermomechanical Processing of Microalloyed Austenite, A.J. DeArdo, G.A. Ratz, and P.J. Wray, eds. TMS-AIME, Warrendale, PA, 1982, pp. 217–36.
T. Senuma, and H. Yada: inAnnealing Processes, N. Hansen, D.J. Jensen, T. Leffers, and B. Ralph, eds., Risø National Laboratory, Roskilde, Denmark, 1986, pp. 547–52.
C. Rossard: inMicrostructure and Design of Alloys, The Institute of Metals and The Iron and Steel Institute, London, U.K., 1973, vol. II, pp. 175–203.
A. Le Bon:Met. Sci. J., 1975, vol. 9, pp. 36–40.
C.M. Sellars, and J.H. Beynon: inHigh Strength Low Alloy Steels, D.P. Dunne and T. Chandra, eds. Australasian Institute of Metals, Wollongong, Australia, 1984, pp. 142–50.
R.B. Sims:Proc. Inst. Mech. Eng., 1954, vol. 168, pp. 191–219.
M.J. Luton, and C.M. Sellars:Acta Metall., 1969, vol. 17, pp. 1033–43.
J.J. Jonas, and T. Sakai: InDeformation, Processing, and Structure, G. Krauss, ed., ASM, Metals Park, OH, 1984, pp. 185–243.
J.P. Sah, G.J. Richardson, and C.M. Sellars:Indian J. Technol., 1973, vol. 11, pp. 445–52.
R. Sandström, and R. Lagneborg:Acta Metall., 1973, vol. 23, pp. 387–98.
Coladas, J. Masounave, G. Guerin, and J.P. Bailon:Met. Sci. J., 1977, vol. 11, pp. 509–16.
C.M. Sellars: inDeformation, Processing, and Structure, G. Krauss, ed., ASM, Metals Park, OH, 1984, pp. 245–77.
C. Ouchi, and T. Okita:Trans. Iron Steel Inst. Jpn., 1982, vol. 22, pp. 543–51.
I. Tamura, C. Ouchi, T. Tanaka, and H. Sekine:Thermo-mechanical Processing of High Strength Low Alloy Steels, Butterworth's, London, U.K., 1988.
S.S. Hansen, J.B. Vander Sande, and M. Cohen:Metall. Trans. A, 1980, vol. 11A, pp. 387–402.
M. Umemoto, Z.H. Guo, and I. Tamura:Mater. Sci. Technol., 1987, vol. 3, pp. 249–55.
Author information
Authors and Affiliations
Additional information
Y.W. BOWDEN, formerly CSIRA Research Associate, Department of Mining and Metallurgical Engineering, McGill University
Rights and permissions
About this article
Cite this article
Bowden, J.W., Samuel, F.H. & Jonas, J.J. Effect of interpass time on austenite grain refinement by means of dynamic recrystallization of austenite. Metall Trans A 22, 2947–2957 (1991). https://doi.org/10.1007/BF02650254
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02650254