Mitigating Corrosion in Mild Steel by Sodium Tungstate Based Inhibitors in Neutral Aqueous Medium

摘要

In practice, tungstates are seldom used alone in open recirculating cooling water systems due to their low oxidizing ability and high cost. The objective of the present work is to increase the inhibition efficiency of sodium tungstate(ST) by means of its synergistic effects with sodium silicate(SS) and sodium phosphate(SP), especially at lower concentrations with a view of its application to cooling water systems. All the synergistic combinations studied in the present work reveal high inhibition efficiency than the individual inhibitors. Among these synergistic combinations, 4:1 ratios of sodium silicate and sodium phosphate with sodium tungstate, namely 800 ppm SS + 200 ppm ST and 800 ppm SP + 200 ppm ST show highest inhibition efficiency.