DefinePK

Abstract

Based on the analysis of literature data and our own experimental studies, the contribution of various strengthening mechanisms to the yield strength of carbon, wheel and low-alloy steels has been quantified. It is established that for normalized steel (St5ps) the greatest contribution to the yield strength is made by hard-solution and grain boundary hardening (37.0 % and 28.0 %), and for low-alloy steel 16G2AF, along with these hardening components, the role of dispersion hardening (21.4 %) is noticeable. It is shown that thermomechanical treatment of St.5ps steel leads to the growth of dislocation hardening up to 27.6 % due to the growth of dislocation density and preservation of most dislocations in the rolled products at accelerated cooling of hot-deformed austenite. In wheel steels heat-treated using conventional technology (intermittent hardening and tempering), grain boundary hardening and dislocation hardening (31.5; 23.4%, respectively) make a major contribution to the yield strength. In the same steel, which is treated with surface plasma hardening, the share of grain boundary hardening in the total yield strength increases significantly (54.7%) due to strong structure refinement.