No abstract

No abstract

The paper presents the experimental data on the temperature dependence of mechanical properties and plastic flow behavior of cast alloys Fe 20 Cr 20 Mn 20 Ni 20 Co 20-x C x (x = 0, 1, 3, 5) in the temperature range from 77 to 297 K. In the as-cast state, high-entropy Cantor alloy Fe 20 Cr 20 Mn 20 Ni 20 Co 20 and multicomponent alloy Fe 20 Cr 20 Mn 20 Ni 20 Co 19 C 1 have an austenitic structure, while carbon doping results in solid solution strengthening of austenitic grains and carbide precipitation at the grain boundaries. The temperature dependence of the yield stress for the Fe 20 Cr 20 Mn 20 Ni 20 Co 19 C 1 alloy significantly exceeds the σ 0.2 (T) dependence for the Fe 20 Cr 20 Mn 20 Ni 20 Co 20 alloy. Carbon-assisted solid solution strengthening is accompanied by an increase in flow stress and strain hardening as well as by a decrease in low-temperature plasticity in the

The microstructure, deformation mechanisms, tensile properties and fracture micromechanisms of ultrahigh-interstitial austenitic Fe-22Cr-26Mn-1.3V-0.7C-1.2N (mass.%) steel were investigated in wide temperature interval. After conventional homogenization and solid-solution treatment, the steel possesses complex hardening which includes grain boundary, solid-solution and dispersion strengthening. In the temperature interval of −60 to +60 °C, steel demonstrates striking temperature dependence of a yield strength which could be enhanced by the increase in solid-solution treatment temperature. The variation in test temperature does not change the dominating deformation mechanism of the steel, dislocation slip and insufficiently influences tensile elongation and fracture micromechanisms. The insignificant increase in the fraction of brittle cleavage-like component on the fracture surfaces of the specimens in low-temperature deformation regime is promoted by increase in planarity of dislocation arrangement and the gaining activity of mechanical twinning. In high-temperature range (200–300 °C) of deformation, a negative strain-rate dependence, serrations on the stress-strain diagrams and improved strain-hardening associated with a dynamic strain aging phenomenon have been observed.