This paper reviews several important aspects of molybdate inhibition, and outlines how it can be efficiently employed in practice. The data presented includes some little-known work on in-situ pitting corrosion measurements featuring proton-induced characteristic x-ray emission and D.C. Impedance, and new data from unpublished work done in the UK. Synergism, mechanism and pitting inhibition are covered in some detail. Further work reviewed includes D.C. Polarization and electrochemical noise experiments. The paper presents a full appreciation of a proposed mechanism to explain synergism with certain polymers and other corrosion inhibitors, based on surface absorption of so called "molybdo-phillic" entities, which attract molybdate anions and bind them loosely by what may be regarded as week hydrogen bonds. A useful bibliography of valuable references on the subject is also included.

97-08: Twenty Minutes with Molybdate

  • M.H.L. Garnaud, Climax Molybdenum UK, Ltd; Thomas J. Risdon, Climax Molybdenum Marketing Corporation