Coarsening kinetics of Cu-rich precipitates in a concentrated multicomponent Fe-Cu based steel

The coarsening kinetics of Cu-rich precipitates in a concentrated multicomponent Fe-Cu based steel, containing 1.12at.%Cu, aged at 550 °C or at 550°C plus 2h at 200 °C is investigated. The temporal evolution of the precipitates, heterophase interfaces, and α-Fe matrix compositions and precipitate morphology are presented. Coarsening time exponents are determined for the mean radius, (R(t)-, and number density, NV(t), and compared to the Lifshitz-Slyzov-Wagner model for coarsening, modified for concentrated multicomponent alloys by Umantsev-Olson. The experimental results indicate that (R(t)) and Nv(t) are in reasonable agreement with Umantsev-Olson model behavior. Additionally, we compare the results to earlier investigations of similar concentrated multicomponent steels containing 1.82 at.% Cu and 1.17 at.% Cu, aged at 500 °C.