Dealloying of 304L Stainless Steel in Boiling Caustic Environments and the Effect of Lead

Abstract

An electrochemical study was conducted on 304L stainless steel (SS 304L) in 10-50% NaOH solution at boiling using a bench-top set up. The range of pH in which the selective dissolution of the reactive alloying elements (dealloying) occurs and was observed. The effect of surface strain and addition of impurities (Pb) on re-activating the dealloying behavior were evaluated. The results show that the dealloying behavior of SS 304L stops at approximately 10% NaOH. The application of strain was found to disrupt the protective oxide, accelerating dealloying. The addition of Pb was found to shift the corrosion potential into the dealloying or passive regime.