Hot hardness and indentation creep studies of a Fe–28Al–3Cr–0.2C alloy

The hot hardness behaviour of a Fe–28Al–3Cr–0.2C (at.%) alloy was evaluated from room temperature to 1273 K. Indentation creep measurements were also carried out in the temperature range of 843–963 K. The hardness–temperature plot of this alloy showed five distinct regions. The mechanism of deformation operating in each of these regions has been suggested. Indentation creep measurements showed that the stress exponent (n) obtained from the hardness–time plots was weakly temperature dependent. The activation energy for high temperature creep was found to be in good agreement with that for self-diffusion of pure iron and in excellent agreement with previous studies. These values of n and activation energy were found to be consistent with dislocation climb as the rate controlling creep mechanism.