Abstract: A process for inhibiting corrosion of metal surfaces, such as steel, in a closed system which comprises maintaining in such system a composition containing a major amount of an oleaginous vehicle, such as petroleum hydrocarbon, and minor amounts of an oil-soluble hydrophilic cosolvent, such as a wetting agent, and the reaction product of substantially equimolar proportions of a dicyclohexylamine, such as dicyclohexylamine itself, and a C.sub.7 organic acid, such as heptanoic acid and cyclohexane carboxylic acid, wherein such heptanoic acid is preferably obtained by the oxidation of C.sub.7 aldehydes resulting from the oxonation of C.sub.6 alpha olefins.