Abstract
Effect of cathodic current on the corrosion of 18-8 stainless steel in various acid and salt solutions was studied. It was found that 18-8 stainless steel suffers cathodic corrosion at certain current densities in dilute HCl, HNO3, H2SO4 and NaCl solutions, but this corrosion can be protected by higher cathodic current as shown in Fig. 3, 5, 6 and 7. This cathodic corrosion is due to the breakdown of protective oxide film on 18-8 stainless steel by hydrogen evolved on the cathod surface by electrolysis of the solutions, but such active stainless steel can be protected by a higher cathodic current. This mechanism is schematically illustrated in Fig. 8a and 8b.
