Corrosive Behaviors of Crude Oils and their Effects on Ferrous Metals

Abstract

Crude oil is an essential natural resource regarding the day today industrial applications within adverse experiences on some materials such as the corrosion on metals which is usually known as the formation of metal oxides, sulfides or hydroxides on the metal surface itself. In the current research there were considered the effect of elemental sulfur, mercaptans, organic acids and salts on the corrosion rates of seven different types of ferrous metals. The chemical compositions of ferrous metals were detected by XRF detector. Such corrosive properties of both crude oils were tested by standard methods and adequate instruments. A set of equal sized metal coupons from each metal type were immersed in both crude oils separately and the corrosion rates of each type of metal was determined in order to 15, 30 and 45 days from the immersion by the weight loss method while observing the corroded metal surfaces through an optical microscope. The initial hardness and the hardness after corrosion on each metal coupon were tested by Vicker’s hardness tester and the both ferrous and copper concentrations in each crude oil sample were tested by atomic absorption spectroscopy after the interaction with metals. According to the results there were observed strong corrosive tendency from Das Blend crude oil than the Murban crude oil. There were found relatively higher corrosion rates of carbon steels, relatively lower corrosion rates of stainless steels and intermediate corrosion rates form Monel in both crude oils. Most of metals showed some higher corrosion rates in Murban crude oil than the corrosion rates of the same metal in Das Blend crude oil eventually.