We investigated phase content and distribution of stresses (contact and residual) over the surface layer depth of cold-rolling rollers. The results of this investigation were applied to description of the initiation mechanism for defoliations. A defoliation is initiated in the zone of maximum tensile residual stresses at the interface of phase microinclusions. Defoliation evolution includes four stages: in-depth nucleation of microcracks, development of the main crack, its stable propagation, and final fracture. Crack opening is enhanced by stresses and structural breakdown of residual austenite under action of rolling cycling loads. In order to reduce the probability of exfoliation initiation, roller heat treatment modes should be optimized.
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