ELECTROCHEMICAL-BEHAVIOR OF THE 316L STAINLESS-STEEL IN CHLORITE SODIUM BLEACHING PROCESS

This paper is devoted to study the electrochemical behaviour of 316L stainles steel in chlorite sodium cotton bleaching process. Experimental investigations provide the following informations : In the corrosion potential neighborhood, standard electrochemical and impedance measurements evidenced a mass transfer charge transfer process limitations at the electrode. In the potential range - 600, - 200 mv vs. SCE, a diffusion limited current, i(L), is evidenced. Further, the i(L) current is linked to the square root of the rotating electrode speed, w , by a linear function ; with a shift at the axis origin. This shift may be related to a probable adsorption phenomenon. The hypothetic pitting corrosion phenomenon is the consequence of the presence of Cl- ions which is induced by the pH solution. The presence on Auger spectra of a chlorine peak, would mean that breaking of passive film is very sensitive to chloride ions.