Abstract
A correlation was confirmed between the good low temperature Charpy toughness of 9Ni steel and the stability of its precipitated austenite against the martensitic transformation. Changes in the microstructure during isothermal tempering were studied in detail. The austenite/martensite interface is originally quite coherent over ∼100 A distances. With further tempering, however, the dislocation structure at the austenite/martensite interface changes, and this change may be related to the increased instability of the austenite particles. The reduction in austenite carbon concentration does not seem large enough to account for the large reduction in austenite stability with tempering time. The strains inherent to the transformation of austenite particles create dislocation structures in the tempered martensite. The large deterioration of the Charpy toughness of overtempered material is attributed, in part, to these dislocation structures.
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G. R. Brophy and A. J. Miller:Trans. ASM, 1949, vol. 41, p. 1185. 2. A.W. Pense and R.D. Stout: Weld. Res. Council Bull. 205, 1975.
C.K. Syn, B. Fultz, and J.W. Morris, Jr.:Metall. Trans. A, 1978, vol. 9A, p. 1735.
C.K. Syn, S. **, and J.W. Morris, Jr.:Metall. Trans. A, 1977, vol. 7A, p. 1827.
S.K. Hwang, S. **, and J.W. Morris, Jr.:Metall. Trans. A, 1975, vol. 6A, p. 2015.
J.I. Kim and J.W. Morris, Jr.:Metall. Trans. A, 1981, vol. 13A, p. 1957.
C.W. Marschall, R. F. Hehemann, and A.R. Troiano:Trans. ASM, 1972, vol. 55, p. 135.
T. Ooka and K. Sugino:J. Japan Inst. Metals, 1976, vol. 30, p. 435.
T. Ooka, H. Mimura, S. Yano, K. Sugino, and T. Toizumi:J. Japan Inst. Metals, 1976, vol. 30, p. 442.
H. Sakurai, S. Yano, T. Inoue, H. Mimura, and K. Aoki:J. Japan Inst. Metals, 1969, vol. 33, p. 857.
K. J. Kim and L. H. Schwartz:Mater. Sci. Eng., 1978, vol. 33, p. 5. 12. T. Funekoshi: Ph.D. Thesis, Tohuku Univ., Japan, 1973.
S. Nagashima, T. Ooka, S. Sekino, H. Mimura, T. Fujishima, S. Yano, and H. Sakurai:Trans. Iron Steel Inst. Japan, 1971, vol. 2, p. 402.
J.R. Strife and D.E. Passoja:Metall. Trans. A, 1980, vol. 11A, p. 1341.
M. Kron, A. Constant, A. Clerc, J. Plateau, G. Henry, M. Robert, and C. Crussard:Memoires Scientifiques Rev. Metallurg., 1971, vol. 58, p. 901.
D. Hardwick:Iron Steel, 1971, vol. 34, p. 414.
H. Haga:Trans. Iron Steel Inst. Japan, 1973, vol. 13, p. 141. 18. B. Fultz: M.Sc. Thesis, Univ. of California, Berkeley, CA, 1978.
B. Fultz and J.W. Morris, Jr.:Metall. Trans. A, 1985, vol. 16A, p. 173. 20. J. I. Kim: Ph.D. Thesis, Univ. of California, Berkeley, CA, 1979.
J.W. Mrris, Jr., C.K. Syn, J.I. Kim, and B. Fultz: Proc. Inter. Conf. Martensitic Transform., 1979, MIT, Cambridge, MA, p. 573.
J.I. Kim, C.K. Syn, and J.W. Morris, Jr.:Metall. Trans. A, 1983, vol. 14A, p. 93.
S.D. Antolovich, A. Saxena, and G.R. Chanani:Metall. Trans., 1974, vol. 5, p. 623. 24. B. Fultz: Ph.D. Thesis, Univ. of California, Berkeley, CA, 1982. 25. B. Fultz, J.I. Kim, and J.W. Morris, Jr.: Univ. of California, Berkeley, CA, unpublished research.
B. Fultz and J.W. Morris, Jr.:Metall. Trans. A, 1985, vol. 16A, p. 2251. 27. Annual Book of ASTM Standards, E-23 “Notched Bar Impact Testing of Metallic Materials”, and A-370 “Mechanical Testing of Steel Products”, ASTM, Philadelphia, PA, 1980. 28. N.I. Sax: Dangerous Properties of Industrial Materials, Van Nostrand Reinhold, New York, NY, p. 890.
R. L. Miller:Trans. ASM, 1964, vol. 57, p. 893. R. L. Miller: Trans. ASM, 1968, vol. 61, p. 593.
B. Fultz and J. W. Morris, Jr.:Rev. Sci. Instr., 1978, vol. 49, p. 1216. 31. B. Fultz: Radiation Detector, 1983, U.S. Patent #4,393,307.
B. Fultz and J. W. Morris, Jr.:Nucl. Instr. Methods, 1981, vol. 188, p. 197. B. Fultz and J.W. Morris, Jr.: Nucl. Instr. Methods, 1983, vol. 211, p. 569.
S. Margulies and J.R. Ehrman:Nucl. Instr. Methods, 1971, vol. 1, p. 131. S. Margulies, P. Debrunner, and H. Frauenfelder: Nucl. Instr. Methods, 1973, vol. 21, p. 217.
G. Kurdjumov and G. Sachs:Z. Physik, 1930, vol. 64, p. 335.
J.I. Kim and J.W. Morris, Jr.:Metall. Trans. A, 1980, vol. 11A, p. 1401. 36. W. B. Pearson: A Handbook of Lattice Spacings and Structures of Metals and Alloys, Pergamon Press, New York, NY, 1958.
A. D. Rmig, Jr. and J. I. Goldstein:Metall. Trans. A, 1978, vol. 9A, p. 1599.
N. Ridley, H. Stuart, and L. Zwell:Trans. AIME, 1979, vol. 245, p. 1834.
Z. Nishiyama as referenced by Pearson, ibid.,. and Sci. Rep. Tohoku Imp. Univ., 1935, vol. 24, p. 128.
B.P.J. Sandvik and CM. Wayman:Metall. Trans. A, 1983, vol. 14A, p. 823.
W. G. Dobson and D.L. Johnson:Adv. Cryogenic Eng. Materials, R. P. Reed and A.F. Clark, eds., Plenum Press, New York, NY, vol. 30, in press.
G. Krauss, Jr.:Acta Metall., 1973, vol. 11, p. 499.
Y. H. Kim: unpublished results, Univ. of Calif., Berkeley, CA, 1983.
H. J. Kim and H. Shin: unpublished results, Univ. of Calif., Berkeley, CA, 1982.
Metals Handbook, 9th ed., ASM, Metals Park, OH, 1978, vol. 1, pp. 458, 472, 530.
Glossary of Metallurgical Terms and Engineering Tables, ASM, Metals Park, OH, 1979, p. 89.
M. O. Peach and J.S. Koehler:Phys. Rev., 1950, vol. 80, p. 437.
J.P. Hirth and J. Lothe:Theory of Dislocations, McGraw-Hill, New York, NY, 1968, p. 102.
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Fultz, B., Kim, J.I., Kim, Y.H. et al. The stability of precipitated austenite and the toughness of 9Ni steel. Metall Trans A 16, 2237–2249 (1985). https://doi.org/10.1007/BF02670423
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DOI: https://doi.org/10.1007/BF02670423