The effect of sulfide on the aerobic corrosion of carbon steel in near-neutral pH saline solutions

Severe corrosion damage may occur when gas transmission pipelines are exposed, at disbanded coating locations, to trapped waters containing sulfide followed by secondary exposure to air. Aerobic corrosion with sulfide was investigated in a long-term corrosion experiment in which corrosion was monitored by measurement of the corrosion potential and polarization resistance obtained from linear polarization resistance measurements. The properties and composition of the corrosion product deposits formed were determined using scanning electron microscopy, energy dispersive X-ray analysis, and Raman spectroscopy. A switch from aerobic to aerobic-with-sulfide corrosion doubles the relative corrosion rate. (C) 2012 Elsevier Ltd. All rights reserved.