CORROSION INHIBITORS

The scientific and technical corrosion literature has descriptions and lists of numerous chemical compounds that exhibit inhibitive properties. Of these, only very few are actually used in practice. This is partly due to the fact that the desirable properties of an inhibitor usually extend beyond those simply related to metal protection. Therefore, the principles and practice of corrosion inhibition have been described in terms of the factors affecting inhibitor performance and selection i.e. principles and the more important practical situation in which inhibitors are used. For the latter a brief account is given of the nature of the system, the reasons for inhibitor application and the types of inhibitors in use. A host of examples of corrosion inhibitors being used in industry and their related dependents on certain factors have been described. Then various theories for the action of inhibitors and methods of studying inhibitors have also been discussed in detail. Considerations of cost, toxicity, availability and environmental friendliness are of considerable importance. The extensive use of inhibitors is obvious, but emphasis is placed on the factors affecting their performance and on the specific circumstances and other requirements relating to a particular application. From the quantum of literature available on the use of corrosion inhibitors it can be very aptly described as an old remedy for new challenges. The importance of inhibitors will never be undermined at any point of time in future. K e y w o r d s : corrosion, inhibitors, aggressive media, metals and alloys.