CORROSIVE TRENDS OF MINERAL OILS AND EFFECTS OF SUCH DISTINCTIVE COMPOSITES ON THE METALS

Abstract

The investigations of the impact of corrosive properties in mineral oils on the corrosion rates of different types of metals and the nature of such corrosion with respect to the corrosive compounds of mineral oils and the metal types were the aims and objectives of the research. The corrosive properties of two different types of selected crude oils and the chemical compositions of seven different types of ferrous metals were tested by the standard instruments and methodologies. The corrosion rates of the similar sized prepared metal coupons were determined by the relative weight loss method after certain immersion time periods in both crude oils. In addition, the corroded surfaces were observed by the optical microscope and analysed, decayed ferrous and copper amounts from metals into crude oils were tested by the atomic absorption spectroscopy (AAS) and the reductions of the initial hardness of the metal coupons were tested by the Vicker’s hardness tester. As the results ultimately there were found the higher corrosion rates from carbon steels, lower corrosion rates from stainless, intermediate corrosion rates from Monel metal, higher impact from salts on the metallic corrosion when comparing with other compounds, formation of FeS, Fe2O3 rarely, corrosion cracks and pitting corrosion, higher amounts of decay of ferrous and copper from some metals into crude oils and slight reductions of the initial hardness of most of metals.

Keywords

• mineral oils
• corrosive trend
• ferrous metals
• weight loss
• decay
• hardness