The Effect of Solution Treatment Regime on Temperature Dependence of 0.2 Offset Yield Strength in V-Alloyed High-Nitrogen Austenitic Steel

摘要

The effect of solid solution temperature (1100 and 1200°C) on microstructure, phase composition and temperature dependence of 0.2% offset yield strength R_(0 2), in the temperature range of 77 to 673 K was studied for high-nitrogen austenitic Fe-19Cr-21Mn-1.5V-0.3C-0.9N (wt. %) steel. Increase in solid solution temperature provides a partial dissolution of (V, Cr)(N, C) particles and increases a concentration of carbon and nitrogen in austenite. A complex effect of solid solution hardening and particle strengthening provides strong temperature dependence of the yield strength in the steel independently on solid solution temperature. The mechanisms, responsible for the variation in the yield strength with test temperature and solution treatment, are described on the basis of the microstructural parameters of the steel.