RESEARCH ON CORROSION INHIBITION PERFORMANCE OF NON-PHOSPHORUS COMPOSITE CORROSION INHIBITOR FOR CARBON STEEL, COPPER AND STAINLESS STEEL

One highly efficient non-phosphorus corrosion inhibitor was developed from gamma polyglutamic acid (gamma-PGA), polyaspartic acid (PASP) and benzotriazole (BTA). Its corrosion inhibition performances' for carbon steel, copper and stainless steel were evaluated by electrochemical, rotary hanging-piece and dynamic simulation. The results illustrated that the corrosion inhibitor was a cathodic polarisation-based suppression of mixed-type water treatment agent and its corrosion inhibiting rates were 82% (carbon steel), 95% (copper) and 99% (stainless steel), respectively. Electrochemical impedance spectroscopy (EIS) showed that the dense protective films between corrosion inhibitor and metals could inhibit these corrosion rates. Further dynamic simulated test also indicated that the corrosion inhibitor met the requirements of circulating cooling water.