Effect of Annealing on Precipitation Hardening Behavior of 4% Al Austenitic Steel During Creep

ustenitic steel AFA alloyed with 4% Al is studied in the state as delivered and after annealing at 1050 and 1230°C. The chemical composition of the steel is determined, the microstructure is analyzed, and the morphology of the secondary phases is studied using scanning electron microscopy and diffraction analysis. The high-temperature creep curves are plotted. The variation of the properties of the steel is analyzed after the creep tests. The annealing is shown to affect positively the creep resistance of steel AFA. The parameters of high-temperature creep are higher after the annealing at 1230°C; the rate of steady creep is equal to 1.61 × 10 – 6 sec – 1 ; the activation energy is 608.2 kJ/mole.