Corrosion-erosion wear is a complex mechanism of material degradation resulting from simultaneous electrochemical and mechanical processes. Serious economic consequences of corrosion-erosion are expressed in failure of oil and gas equipment components, pipelines, and increased downtime and maintenance costs. The authors evaluated the corrosion resistance of pipe steels, the effectiveness of corrosion inhibitors, epoxy coatings as methods of anti-corrosion protection of equipment in the presence of mechanical impurities. As a result of the research, it was found that the presence of mechanical impurities causes increase in corrosion rate of carbon and low-alloy steels by 30-50%, depending on gas-liquid velocity. The most negative effect of mechanical impurities is appeared at high flow rates. Significant difference in comparable test conditions for steels containing chromium in an amount of 0.5% wt. and chromium-free have not been identified. Polymeric epoxy coatings are effective in preventing corrosion-erosion; however, their use in environments containing mechanical impurities and at high flow rates requires separate wear tests. Water-soluble corrosion inhibitor for protection against corrosion-erosion has been studied. It has been shown that use of a corrosion inhibitor in basic dosages (25 mg/l) is not effective. A possible mechanism for low efficiency of corrosion inhibitor at the indicated dosage is inhibitor adsorption on mechanical impurities and/or the breakdown of the corrosion inhibitor film during the mechanical action of suspended particles on metal surface. At higher dosages, the corrosion inhibitor effectively reduces the corrosion-erosion rate.
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