The effectiveness of molybdate as a corrosion inhibitor in cooling water systems has been studied. The historical comparison to chromate is not appropriate because of chromate's greater oxidizing ability. Molybdate can function as a localized corrosion inhibitor for mild steel. Laboratory studies indicate that molybdate may be effective when used in conjunction with cathodic and other anodic inhibitors. Comparative cooling tower tests with and without molybdate illustrate conditions where molybdate has a beneficial effect.
90-13: Effects of Molybdate in Cooling Water Treatment Programs
Kenneth P. Fivizzani & Sang-Hea Shim, Nalco Chemical Company