Experimental Study on Top-of-Line Corrosion Behavior of X65 Steel by Crude Oil postprint

Abstract: The corrosion behavior of different locations of X65 steel oil pipeline was investigated using a high-temperature corrosion test chamber, which aims to simulate the real corrosive environments of oil pipelines. Then the morphology and composition of the corrosion scales were characterized by Scanning Electron Microscope (SEM), Energy Dispersive Spectrometer (EDS) and Xray diffraction (XRD). The results demonstrated that with the increasing time, the corrosion rate of X65 steel increased firstly and then slowed down to a lower level for long term. While temperature has obvious influence on the corrosion rate of the X65 steel, which presented the top area of the pipeline, where the steel suffered from uniform corrosion with formation of water drop-like corrosion products adhere to the steel surface. At low temperature, the main component of the corrosion products were iron oxide, in the contrast, at high temperature a protective corrosion product composed mainly of Fe2S could form.