EVALUATION OF CORROSION-INHIBITORS FOR COMPONENT COOLING WATER-SYSTEMS

Electrochemical techniques were used to study the inhibition effects o f molybdate (MoO42-), MoO42- + nitrite (NO2-), MoO42- + tolyltriazole (TTA, CHCHNH), and MoO42- + NO2- + TTA on the general and pitting/crev ice corrosion of carbon (C) steel and some copper (Cu) alloys common t o component cooling water systems (CCWS) exposed to deionized water op en to ambient air or purged with nitrogen (N2). Some tests were perfor med in deionized water faulted with chloride (Cl-) at concentrations o f 150 ppb or 1.5 ppm and with 1.5 ppm Cl-plus 1. 5 ppm sulfate (SO42-) . Results were compared with the inhibition effects of 200 ppm chromat e (CrO42-).