Abstract
A study has been made of the fracture toughness of AISI M2 and M7 high-speed steels. Fracture toughness of these steels was found to depend principally on austenitizing temperature and hardness level. The results are highly reproducible. At usual working hardness levels the fracture toughness of M7 and M2 were approximately equal. Instrumented unnotched Charpy tests showed M2 to have higher impact strength than M7. A model for fracture that assumed preexisting flaws was tested with the data obtained. The model is consistent with the results obtained for M7 but not for M2. The assumption of preexisting flaws in M2 high-speed steel does not seem warranted. Possible mechanisms for crack initiation in M2 are discussed briefly.
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A. H. Grobe and G. A. Roberts:Trans. Amer. Soc. Metals, 1948, vol. 40, p. 435.
A. H. Grobe and G. A. Roberts:Trans. Amer. Soc. Metals, 1950, vol. 42, p. 686.
H. H. Weigand:Iron Steel Inst., London, Publ. 126, p. 176, 1970.
E. J. Dulis:Iron Steel Inst., London, Publ. 126, p. 177, 1970.
K. Eriksson:Scand. J. of Metall., 1973, vol. 2, p. 197.
U. Häfke, H. Blumenauer, and G. Pusch:Neue Huette, 1974, no. 1, vol. 19, p. 54.
D. E. Diesburg: ASTM STP 559, p. 3, 1974.
W. Oldfield, W. L. Server, and R. A. Wullaert:J. Appl. Meas., 1972, no. 1, vol. 1, p. 11.
A. F. Grandt, Jr. and G. M. Sinclair: ASTM STP, 513, p. 37, 1972.
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Johnson, A.R. Fracture toughness of AISI M2 and AISI M7 high-speed steels. Metall Trans A 8, 891–897 (1977). https://doi.org/10.1007/BF02661570
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DOI: https://doi.org/10.1007/BF02661570