Fb. Waanders et al., The influence of temperature on sigma-phase formation and the resulting hardening of Fe-Cr-Mo-alloys, HYPER INTER, 121(1-8), 1999, pp. 751-755
Hardening in Fe-Cr-Mo-alloys due to the formation of sigma-phase, has been
the subject of theoretical and experimental interest. In the present invest
igation Fe-Cr-alloys containing 0, 2, 4 and 6% Mo were prepared and were fu
lly transformed to the sigma-phase by isothermally annealing the samples fo
r various periods at temperatures of 600-800 degrees C. After each annealin
g cycle room temperature CEMS-spectra were recorded and micro-hardness test
s were performed. The micro-hardness increases with annealing time and temp
erature, in accordance with the fraction of sigma-phase present, and ranged
from about 140 HV to 200 HV. From the measurements, activation energies we
re also deduced.