The influences of the crude oils on the decay of metals

Crude oils are the essential resources for the usages of industrial purposes in various forms and the refining is a key process of separating the mixture of raw crude oils. In the existing research there were expected to investigate the impact of salts, organic acids, mercaptans and elemental sulfur of crude oils on the corrosion rates of seven different types of ferrous metals in both qualitatively and quantitatively. The chemical compositions of such selected ferrous metals and the above mentioned corrosive properties of two different types of crude oils were measured by the standard instruments and methodologies. A set of similar sized metal coupons were prepared from seven different types of metals and the corrosion rates of such metals were determined by the relative weight loss method. In addition, that the corroded metal surfaces were analyzed under the microscope, decayed metal concentrations and deductions of the initial hardness of metal coupons were measured. According to the obtained results that there were observed the lower corrosion rates from stainless steels with at least 12% of chromium and nickel, higher corrosive impact from salt, formations of FeS, Fe2O3, corrosion cracks and pitting corrosion.