Galvanic Corrosion Behavior of Two Groups of Heterogeneous Stainless Steel Galvanic Couples in Sodium Chloride Solution

The galvanic corrosion behavior of 316L/2205 and 1Cr17Ni2/2205 heterogeneous stainless steel galvanic couples in 3.5%NaCl solution was studied,and their potentiodynamic polarization curves as well as coupling potential and coupling current density at different ratios of calhodic area to anodic area were compared.Results showed that,as compared with316L/2205 galvanic couple,the 1Cr17Ni2/2205 galvanic couple exhibited a larger corrosion potential difference,a smaller coupling potential,and a higher coupling current density,which meant that the latter was more liable to galvanic corrosion than the former.Besides,with the increase of the ratio of cathodic area to anodic area,the coupling potential decreased and the coupling current density increased.After the two groups of galvanic couples underwent 48 h of galvanic corrosion tests under the same conditions,noticeable corrosion products were deposited on the surface of 1Cr17Ni2.but no obvious corrosion products were observed on the surfaces of 2205 and 316 L stainless steels.