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When present as vapors, certain organic compounds offer inhibition against the corrosion of ferrous and nonferrous materials. The inhibitors include aliphatic, aromatic, cyclohexylamines, aminonitrobenzoates, heteroalkylated lower amines, etc. The mechanism of inhibition offered by these compounds was discussed and an unified mechanism was presented. Various methods of evaluating inhibition efficiency were discussed with a special reference to surface film characterization techniques. Methods of application of the vapor phase inhibitors and their industrial uses also were presented.

This work deals with atmospheric corrosion to assess the degrading effects of air pollutants on ferrous and non-ferrous metals and alloys, which are mostly used as engineering materials. An exposure study was conducted in the Tuticorin port area located on the east coast of South India, in the Gulf of Mannar with Sri Lanka to the southeast. Common engineering materials, namely mild steel, galvanized iron, Zn, Al, Cu and Cu-Zn alloys (Cu-27Zn, Cu-30Zn and Cu-37Zn), were used in the investigation. The site was chosen where the metals are exposed to marine and industrial atmospheres. Seasonal 1 to 12 month corrosion losses of these metals and alloys were determined by a weight loss method. The weight losses showed strong corrosion of mild steel, galvanized iron, Cu and Zn and minor effect on Al and Cu-Zn alloys. Linear regression analysis was conducted to study the mechanism of corrosion. The composition of corrosion products formed on the metal surfaces was identified by x-ray diffraction and Fourier transform infrared spectroscopy.

Corrosion of complex electronic equipment is an increasingly serious problem, causing expensive damage. Corrosion occurs through out the entire life cycle during different stages of manufacturing, assembly, transport and storage of components and assemblies and during field operations of the equipment. Presence of moisture, chloride, sulphur dioxide, hydrogen sulphide and other airborne corrosives, meteorological parameters etc influence the occurrence of corrosion. The present review describes the current understanding mechanism of corrosion of electronic components and equipments in different environmental conditions. The various corrosion testing methods and methods of corrosion prevention in these electronic devices have also been elaborated.

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Potentiodynamic, impedance measurements were carried out on 304 stainless steel in 0.5N, 1.0, 2.0 and 5.0 N H 2 SO 4 solutions. X-ray photoelectron spectroscopic [XPS] The passive film found to contain chromium oxide inner layer and the dissolution of iron through it caused the formation of oxides of iron namely -Fe 2 O 3 and -FeOOH. Higher oxides of manganese and nickel are also due to dissolution through the film. Sulphates are reduced to sulphur chemically by the released protons from anodic polarization.

Natural menthol was coated on craft paper by impregnation and studied as volatile corrosion inhibitor for copper in hydrochloric acid environment. The effect of menthol on copper corrosion was studied by gravimetric and electrochemical methods such as potentiodynamic polarization and electrochemical impedance measurements. The results indicate that menthol adsorbs on the metal surface, which protects copper against further corrosion. The adsorption behaviour of menthol on copper surface was found to obey Temkin's adsorption isotherm.