Theoretical and experimental study of the evolution of the dislocation structure in pearlite during fatigue tests using contact and bending modes of loading was performed. Special features of the dislocation structure of pearlite with a different degree of the structure fineness upon cyclic loading were analyzed. It was shown that a size structural effect was realized in the pearlite, which manifests itself in the dependence of the arising dislocation structure in the ferrite interlayers upon their thickness. The model of the initiation of a fatigue crack in pearlite was developed and the period of its initiation under contact cyclic loading was calculated. Microstructural changes upon the fatigue failure of a high-carbon pearlitic-ferritic steel with different degrees of pearlite fineness were studied electron-microscopically during contact and bending cyclic deformation.

Evolution of the Dislocation Structure and the Formation of Fatigue Microcracks in Pearlitic-Ferritic Steels. V.I.Izotov, V.A.Pozdnyakov, E.V.Lukyanenko, M.E.Getmanova, G.A.Philippov: The Physics of Metals and Metallography, 2008, 105[5], 517-27