On the Anisotropy of the Ductile to Brittle Transition Behavior in a Wrought and in Two Oxide Dispersion Strengthened FeCrAl Steels

Abstract

The directionality of the ductile-brittle transition behavior of two oxide-dispersion-strengthened (ODS) FeCrAl steels with similar chemical compositions, tensile properties, and sub-micrometric grain sizes but different processing routes, and a Zr-particle strengthened FeCrAl steel manufactured by high vacuum melting is discussed. Despite the similarities of the ODS FeCrAl steels, strong differences in the lower and upper shelf energy and the ductile to brittle transition temperature were observed for longitudinal through thickness notched specimens. Although the lower and upper shelf energies of longitudinal surface-notched specimens of ODS FeCrAl steels are similar, a strong difference in the ductile-to-brittle transition temperature is observed. For through-thickness notched and surface-notched specimens taken transversely, the analyzed ODS FeCrAl steels show a similar ductile-to-brittle behavior. In general, the FeCrAl alloy strengthened with Zr-particles presents a more isotropic behavior and a higher ductile-to-brittle transition temperature than the ODS FeCrAl steels. In addition, the upper shelf energy of the FeCrAl steel strengthened with Zr-particles is significantly higher than that of the ODS FeCrAl steels.