2002 Volume 51 Issue 4 Pages 165-172
Crevice corrosion of 304 L- and 316 L-stainless steels has been examined for 7.2 or 1.8Ms in nitric acid solutions with/without RuNO (NO3)3, by measuring the mass loss of the specimen, the amounts of metal ions dissolved, and the galvanic current.
Specimen surface at/around the crevice corroded more vigorously than that without the crevice, and the tendencies became more remarkable at higher HNO3 concentrations, higher temperatures, and with RuNO (NO3)3. Current flowed from the specimen with crevice to the specimen without crevice through a lead wire, when these connected specimens were immersed in a HNO3 solution containing RuNO (NO3)3. The susceptibility to the crevice corrosion was higher on 316L than on 304L stainless steel.
A mechanism on the crevice corrosion of stainless steels in HNO3 solutions is discussed in terms of a catalytic action of Fe3+ ions accumulated on the surface at the crevice.
