Effects of Zr on high temperature deformation and dynamic precipitation of laves phase in Fe–13Cr–5Al–2Mo–0.5Nb–0.4Ta alloy

Abstract

High temperature deformation of Fe–13.5Cr–4.7Al–2.0Mo–0.70Nb–0.40Ta (FeCrAl) and Fe–13.5Cr–4.7Al–2.0Mo–0.45Nb–0.4Ta–0.11Zr (FeCrAl–Zr) alloys was performed at temperatures of 800–1100 °C with the strain rates of 0.01–10 s−1, and the constitutive model was established based on the Arrhenius equation. True strain-stress curves showed dynamic softening in FeCrAl and FeCrAl–Zr alloys. The maximum activation energy showed significantly different bteween FeCrAl (313 kJ/mol) and FeCrAl–Zr (627 kJ/mol) alloys. Due to the stabilizing effect of Zr on Laves phase, precipitate free zone (PFZ) in FeCrAl–Zr alloy was wider than that in FeCrAl alloy at the same strain rate. Low-angle grain boundary (LAGB) and coincident site lattice (CSL) grain boundary both increased in the FeCrAl–Zr alloy.