摘要：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 and Rm = 700 MPa) with stress intensity factor (ΔKth = 18 MPa∙√m and ΔKth = 10 MPa∙√m).
