Rust and Corrosion

The literature reported that the combined action of water and oxygen causes rust while the presence of acids in water causes corrosion. The early literature reported that many fractions of lube oil base stocks can be strongly adsorbed on cast iron, and that this is connected with the presence of molecules having long normal hydrocarbon chains (Groszek, 1962). The more recent literature reported that a severe hydrotreatment and a further reduction in aromatic and sulfur contents of fuels might lead to a decrease in the fuel inherent lubricity causing an increase in the wear of engine components (Hughes et al., 2002). The literature reported on the use of different testing procedures to study the rust and corrosion formation on the metal surface. A comprehensive review of analytical techniques used to analyze solids and their surfaces, including x-ray photoemission spectroscopy (XPS), was published (Yacobi et al., 1994). Solid surfaces are irradiated with x-rays and the emitted energy of photoelectrons is analyzed. The difference between the x-ray energy and the energy of photoelectrons gives the binding energy of the core level electrons. The energy of photoelectrons depends on the excited atoms and therefore gives elemental information. According to the literature, the XPS technique can be used to measure the surface composition, elemental distributions, and interfacial chemical reactions (Nelson, 1994). The early literature reported on the visual standard corrosion ratings which varied from ‘‘0,’’ indicating no rusting, to ‘‘8’’ indicating that the entire metal surface is covered with rust (Hughes, 1969). The more recent literature reported on the similar rusting severity based on the surface coverage (Pillon, 2003a). The rating system for visual evaluation of severity of rusting based on rusting severity or metal surface coverage is shown in Table 10.1.