Abstract
The growth rates of fatigue cracks propagating through the case and into the core have been studied for carburized X-2M steel (0.14 C, 4.91 Cr, 1.31 Mo, 1.34 W, 0.42 V). Fatigue cracks were propagated at constant stress intensities, ΔK, and also at a constant cyclic peak load, and the crack growth rates were observed to pass through a minimum value as the crack traversed the carburized case. The reduction in the crack propagation rates is ascribed to the compressive stresses which were developed in the case, and a pinched clothespin model is used to make an approximate calculation of the effects of internal stress on the crack propagation rates. We define an effective stress intensity, Ke = Ka + Ki, where Ka is the applied stress intensity, Ki = σid 1/2i , σi is the internal stress, and di is a characteristic distance associated with the depth of the internal stress field. In our work, a value of di = 11 mm (0.43 inch) fits the data quite well. A good combination of resistance to fatigue crack propagation in the case and fracture toughness in the core can be achieved in carburized X-2M steel, suggesting that this material will be useful in heavy duty gears and in aircraft gas turbine mainshaft bearings operating under high hoop stresses.
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References
Roy J. Cunningham: “Process for Carburizing High Alloy Steels,” U.S. Patent 3,885,995, May 27, 1975.
D.P. Townsend and E.V. Zaretsky: Report NASA-TP-1731 (N81-14322), Lewis Research Center, Cleveland, OH, November 1980.
R.A. Cary: Teledyne Vasco, Latrobe, PA 15650, private communication, January 1983.
B. L. Averbach, Bingzhe Lou, P. K. Pearson, R. E. Fairchild, and E. N. Bamberger:Metall. Trans. A, 1985, vol. 16A, p. 1253.
M.E. Hilley, J. A. Larson, C.F. Jatczak, and R. E. Rickless:S.A.E. Publication J784a, August 1971.
C. F. Jatczak, J. A. Larson, and S. W. Shin:S.A.E. Publication SP-453, September 1979.
J. A. Rescalvo and B. L. Averbach:Metall. Trans. A, 1979, vol. 10A, p. 1265.
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Averbach, B.L., Lou, B., Pearson, P.K. et al. Fatigue crack propagation in carburized X-2M steel. Metall Trans A 16, 1267–1271 (1985). https://doi.org/10.1007/BF02670331
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DOI: https://doi.org/10.1007/BF02670331