EFFECT OF SHOT PEENING ON FATIGUE PROPERTIES OF STEEL IN DIFFERENT STRUCTURAL STATES

The aim of this paper is to evaluate the effect of shot peening on fatigue properties of dual-phase steels DP 600 in received condition, as well as in condition after different regimes of heat treatment. In the work, there are presented results of tests on smooth samples as well as on samples with stress concentrator (a drilling hole, size d = 4mm). The expectations, that shot peening of flat steel samples improves resistance to fatigue failure, were approved by all tested structural states. The tests on samples with the drilled hole showed, that effect of shot peening on fatigue properties may be negative, if the hole was drilled after shot peening of surface of samples.