Vapor inhibitors for corrosion protection

The corrosion inhibition of ferrous and nonferrous metals during transportation under atmospheric conditions requires the compound that consists of strong surface adsorption, passivation and ability to form strong and stable bonds with the metallic materials. The delicate and yet complex nature ofatmospheric corrosion processes occurring under thin films of electrolyte preordains thetransport mechanism of corrosion inhibitor which- in order to become effective, mustdiffuse through the electrolyte film and cover the substantial portion of the surface. Theexacts mechanism of corrosion is still not known. However, it is supposed that some chemical and physical parameters of inhibitor molecules plays an important role that includes structural features of inhibitor, saturation level of vapor pressure, ability to form physical/ chemical bonds with metal surface, etc. Vapor phase corrosion inhibitor (VCI) plays an important role in protecting the metallic surface from corrosion. They are incorporated into the plastic films that used to envelop the metallic parts. These VCI compounds have appropriate vapor pressure to completely fill the environment, keeping its efficiency against corrosion by the necessary time, with the parts completely covered by the inhibitor, independent of its shape. The present chapter covers the introduction, Mechanism and evaluation of corrosion inhibition using VCI and applications of VCI for protection of ferrous and non-ferrous metals.