Comportamento de anodos de a？o em meio alcalino

by the analysis of the polarization curves recorded from the open circuit potential up to the oxygen evolution region, the behaviour of aisi 301, 310 and 316 stainless steel anodes, in strong alkaline media, is investigated. substrate corrosion/dissolution is observed in the potential domain -0.20 a -0.05 v vs. sce, followed by oxides formation which do not effectively passivate the electrode surface. aiming to enhance the stainless steel stability, a polarization at 0.50 v vs. sce, for longer than 5h period is required. an alternative methodology is presented consisting on the modification of stainless steel surface by the deposition of metallic oxides. it is illustrated for the case of a pb(ii) containing solution providing a film composed by pb3o4 e a-pbo2 when the electrode is polarized at 0.35v vs. sce.