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 deformat ion operating in each of these regions has been suggested. Indentation cree p measurements showed that the stress exponent (n) obtained from the hardne ss-time plots was weakly temperature dependent. The activation energy for h igh temperature creep was found to be in good agreement with that for self- diffusion of pure iron and in excellent agreement with previous studies. Th ese values of n and activation energy were found to be consistent with disl ocation climb as the rate controlling creep mechanism. (C) 2000 Elsevier Sc ience S.A. All rights reserved.