Abstract
The formation of austenite from different microstructural conditions has been studied in a series of 1.5 pct Mn steels that had been heated in and above the intercritical (α+ γ) region of the phase diagram. The influence of variables such as cementite morphology, initial structural state of the ferrite and the carbon content has been assessed in terms of their respective effects on the kinetics of austenite formation and final microstructure. Austenite was found to form preferentially on ferrite-ferrite grain boundaries for all initial structures. The results of this study have shown that the 1.5 pct Mn has lowered both the AC3 and AC1, lines causing large amounts of austenite to form in low carbon steel. The kinetics of austenite formation at 725 °C were not only very slow but also were approximately independent of the amount formed. Austenite appeared to form slightly more rapidly from cold rolled ferrite than from recrystallized ferrite or ferrite-pearlite structures.
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M. D. Rashid, SAE Paper 770164 presented at International Automotive Engineering Congress and Exposition, Detroit, Michigan, March 1977.
S. Hayami and T. Furukawa:Proceedings Microalloying ’75, p.311 Union Carbide Corp., New York, 1977.
A. P. Coldren and G. Tither:J. Metals, April 1978, vol. 30, p. 6.
G. A. Roberts and R. F. Mehl:Trans. ASM, 1943, vol. 31, p. 613.
G. Molinder:Acta Met., 1956, vol. 4, p. 565.
R. R. Judd and H. W. Paxton:Trans. TMS-AIME, 1968, vol. 242, p. 206.
G. R. Speich and A. Szirmae:Trans. TMS-AIME, 1969, vol. 245, p. 1063.
M. Hillert, K. Nilsson and L.E. Torndahl:J. Iron Steel Inst., 1971, vol. 209, p. 49.
H. W. Paxton:Symposium on Transformation and Hardenability in Steels, p. 3, Climax Molydenum Corp., Ann Arbor, Mich., 1967.
J. D. Grozier, H. W. Paxton and W. W. Mullins:Trans. TMS-AIME, 1965, vol. 233, p. 130.
A. E. Nehrenberg:Trans. TMS-AIME, 1950, vol. 188, p. 162.
J. E. Hilliard and J. W. Cahn:Trans. TMS-AIME, 1961, vol. 221, p. 344.
E. E. Underwood:Metals Handbook, 8th ed, p. 37, ASM, Metals Park, Ohio, 1973.
R. Becker and W. Döring:Phys. Chem. J., 1935, vol. 24, p. 719.
K. C. Russell:ASM Seminar on Phase Transformations, p. 219, ASM Metals Park, Ohio, 1968.
J. B. Newkirk:ASM Lectures on Precipitation from Solids Solution, p. 15, ASM, Metals Park, Ohio, 1957.
P. S. Clemm and J. C. Fisher:Acta Met., 1955, vol. 3, p. 70.
R. B. Nicholson:ASM Seminar on Phase Transformations, p. 269, ASM, Metals Park, Ohio, 1968.
P. G. Shewmon:Transformations in Metals, p. 88, McGraw-Hill, New York, p. 1969.
S. F. Dirnfeld and B. M. Koievaar:Met. Trans, 1974, vol. 5, p.1437.
C. Zener:J. Appl. Phys., 1949, vol. 20, p. 950.
D. Turnbul!:Atom Movements, p. 129, ASM, Metals Park, Ohio, p. 1951.
P. G. Shewmon:Diffusion in Solids, p. 172, McGraw-Hill, New York, 1963.
R. E. Reed-Hill:Physical Metallurgy Principles, 690, p. D. Van Nostrand, New York, 1973.
J. B. Gilmour, G. R. Purdy and J. S. Kirkaldy:Met. Trans, 1972, vol. 3, p. 3213.
E. Bain and H. W. Paxton:Alloying Elements in Steel, 2nd ed., p.104, ASM, Metals Park, Ohio, 1966.
J. B. Gilmour, G. R. Purdy and J. S. Kirkaldy:Met. Trans., 1972, vol. 3, p. 1455.
R. A. Grange:Met. Trans. 1911, vol. 2, p. 417.
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Garcia, C.I., Deardo, A.J. Formation of austenite in 1.5 pct Mn steels. Metall Trans A 12, 521–530 (1981). https://doi.org/10.1007/BF02648551
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DOI: https://doi.org/10.1007/BF02648551