Conclusions
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1.
Direct measurement of local strains in fixed microvolumes of a metal undergoing alternating cyclic loading (symmetrical) established the existence of an extremely inhomogeneous strain state in structural elements of the alloy. An increase in the number of load cycles is accompanied by an increase in the inhomogeneous nature of the accumulation of unidirectional microplastic strains: while plastic strain reaches exceptionally large values (several percent) in some individual microvolumes, it remains equal to zero in other places.
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2.
It was shown that the mechanism of development of plastic strain in carbon steels with cyclic loading at stresses below the yield point is based on the local character of the initiation of plastic strain in the weakest elements of the metal structure.
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3.
The micromechanism of the fatigue fracture of a true polycrystalline alloy is based on microinhomogeneous strain and is characterized by the stable fixing of “sources” of increased or reduced strain from the very first load cycles. This is evidence of the large role of the alloy microstructure and grain-boundary properties in determining the kinetics of development of local microstrains. Here the distribution of microstrains by alloy structural element is satisfactorily described by a normal distribution law.
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Literature Cited
G. S. Pisarenko and V. T. Troshchenko, “Fatigue and imperfect elasticity,” in: Problems of Mechanical Fatigue [in Russian], Moscow (1964), pp. 178–193.
A. V. Gur'ev and G. Yu. Stolyarov, “Microscopic studies of slip band growth and laws of damage accumulation in steel in fatigue tests,” in: Strength of Metals under Cyclic Loads [in Russian], Moscow (1967), pp. 71–76.
V. S. Ivanova and V. F. Terent'ev, Nature of Metal Fatigue [in Russian], Metallurgiya, Moscow (1975).
A. V. Gur'ev, G. M. Misharev, and Yu. D. Khesin, “On the reversibility of plastic strain under repeating-alternating loads,” in: Metal Physics and the Strength of Materials [in Russian], Volgograd (1970), pp. 62–70.
A. N. Romanov and M. M. Gadenin, “Methods and equipment for measuring strain during low-cycle loading,” Zavod. Lab., No. 7, 859–868 (1975).
V. G. Tatsii, V. P. Strel'nikov, and Ya. G. Kuzin, “On the connection between the variance of strength parameters and the inhomogeneity of microstrains,” Probl. Prochn., No. 4, 27–30 (1976).
A. V. Gur'ev, G. M. Misharev, A. S. Stolyarchuk, et al., “Effect of stress concentrations on the low-cycle fatigue strength of metals,” Probl. Prochn., No. 11, 11–15 (1974).
V. T. Troshchenko, E. É. Zasimchuk, and N. D. Bega, “Nature of structural defects in the alternating tension-compression of molybdenum single crystals,” Probl. Prochn., No. 4, 38–41 (1975).
S. V. Serensen (editor), Low-Cycle Fatigue Strength [in Russian], Nauka, Moscow (1975).
A. V. Gur'ev and V. P. Tarasov, “Features of the plastic strain mechanism in the low-cycle loading of steel strengthened by surface plastic deformation,” in: Surface Strengthening of Machine Parts and Instruments [in Russian], Kuibyshev (1975), pp. 3–8.
A. V. Gur'ev and M. Sh. Teplitskii, “High-temperature deformation of mild steel with thermal cycling under load,” Izv. Akad. Nauk SSSR, Met., No. 5, 160–165 (1975).
L. G. Mitropol'skii, Techniques of Statistical Computation [in Russian], Nauka, Moscow (1971).
A. V. Gur'ev and G. Yu. Stolyarov, “On the development of microplastic strain during the fatigue of low-carbon steel,” in: Metal Physics and the Strength of Materials [in Russian], Volgograd (1968), pp. 56–65.
A. Abel and H. Muir, “The nature of microyielding,” Acta Metall.,21, No. 2, 99–105 (1973).
A. V. Gur'ev and V. Ya. Mitin, “Investigation of small plastic strains in the cyclic and static deformation of low-carbon steels,” in: Some Problems of the Strength of Metals [in Russian], Leningrad (1975), pp. 32–39.
A. V. Gur'ev and G. V. Malovechko, “On the mechanism of microyielding in polycrystalline alloys,” in: Metal Physics and the Strength of Materials [in Russian], Volgograd (1970), pp. 5–19.
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Volgograd. Translated from Problemy Prochnosti, No. 11, pp. 19–23, November, 1978.
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Gur'ev, A.V., Mitin, V.Y. Features of development of nonuniform microscopic strains and fatigue damage accumulation in carbon steels. Strength Mater 10, 1263–1267 (1978). https://doi.org/10.1007/BF01529663
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DOI: https://doi.org/10.1007/BF01529663