The Effect of Bitumen Coatings on the Corrosion of Low Carbon Steels (API 5l X65)

Abstract

The corrosion behavior of uncoated and cut-back bitumen coated X65 Steel samples are being investigated in environments of different pH (2, 3, 4 and 7). Immersion tests were carried out on the samples at 25oC. The comparison of the corrosion behavior of uncoated, spray-coated and brush-coated X65 steel samples in the different pH media and temperature were observed using the weight measurements approach and visual examination. With 72 hours intervals in the weight measurement of the samples, the weight loss of the uncoatedX65 samples in the pH 2 was more than the pH (3, 4, and 7). This is mostly due to the attack of chloride ions on the surface of the steel. It was also observed that there was different weight gained measurements for both spray-coated and brush-coated samples which is expected to be due to water absorption. The visual examination and weight changes showed that spray-coated samples are more likely to corrode less than brush-coated samples.