C. Mathieu et S. Toesca, EFFECTS OF MODE-I STRESSES ON THE OXIDATION AND FAILURE MECHANISMS OFNI-20CR AND NI-15CR-8FE ALLOYS IN SULFUR-DIOXIDE, Oxidation of metals, 39(3-4), 1993, pp. 155-165
Two alloys, Ni-20Cr and Ni-15Cr-8Fe, as wire specimens, were exposed t
o sulfur dioxide between 325 and 800-degrees-C, with applied external
stresses (mode I). Their mechanical properties have been investigated,
and the variation of their radius has been precised by conductivity m
easurements. For the Ni-20Cr alloy, below 550-degrees-C, the failure p
rocess combines cracking and corrosion: Cr2S3 crystals formed at the t
ip of the cracks facilitate their propagation. Above 550-degrees-C, no
barrier effect is observed, and intergranular corrosion takes place.
For the Ni-15Cr-8Fe alloy, mode-I stresses bolster intergranular corro
sion.