In the article there are presented the results of experimental
analytical study of the similar chemical composition
but differently heat-treated structural steel: mechanical
properties and resistance to cyclic loading. The indicators
of strength, plasticity and cyclic failure process were
determined. Fracture analysis of compact specimens (CT)
was performed with SEM. It was attempted to validate the
relation of mechanical properties (Rm = 500 MPa for
CS500 steel and Rm = 700 MPa for CS700 steel) with
stress intensity factor (ΔKth = 18 MPa∙√m for CS500 steel
and ΔKth = 10 MPa∙√m for CS700 steel)
