Abstract
254 SMO alloy was tested under different applied potentials to study the susceptibility of this alloy to crevice corrosion. XPS measurements have been carried out to detect and define the products that formed on the surface of 254 SMO in 22 % NaCl at 30 degrees C after three days in three situations: without applied potential, at two applied potentials = 300 and 600 mV(SCE). The formation of Fe, Cr and Mo compounds that play a great role to protect the alloy were found. The corroded sample was studied using EIS technique. The morphology of the corroded surface under the washer tooth was studied. The dividing of the corrosion area under the washer teeth is agreement with IR drop theory.