PEPTIDE INTERACTIONS WITH STEEL SURFACES - INHIBITION OF CORROSION AND CALCIUM-CARBONATE PRECIPITATION

Polyaspartate, a polyanionic peptide analog of an oyster-shell protein fraction, inhibited corrosion of AISI 1018 mild steel (UNS G10180) in seawater in a dose-dependent manner. A maximal inhibition of approximate to 60% was obtained af a concentration of 100 mu g mL(-1). Related peptides containing hydrophobic and/or phosphorylated amino acids had corrosion inhibition activities similar to or lower than polyaspartate in fresh and brackish waters. Binding studies demonstrated polyaspartate bound to mild steel in a dose- and time-dependent manner. Evidence for stainless steel (SS) binding was based on inhibition af calcium carbonate precipitation on the SS surface.