Abstract
Prevention of the corrosion damage is key point to assure process safety in the refinery and petrochemical industry. Controlling and stopping corrosion is only possible through the detailed evaluation of all processes related with the corrosion damage.
In this work was proposed a methodology to evaluate the corrosion damage during combustion process in the refinery and petrochemical industry. As a study case the evaluation of AISI 304 and ASTM A335 P5 steels was realized in an atmosphere generated during the combustion process. The corrosion products formed on each material were simulated at 750 °C in the software HSC Chemistry. As a model mixture for the simulation it was used the historical chromatographic records from the gas mixture used in a typical furnace from Barrancabermeja (Colombia) refinery. These results were compared with experimental results, in which corrosion coupons of AISI 304 and ASTM A335 P5 steels were installed inside a furnace from Barrancabermeja refinery at 750 °C. The corrosion rate was calculated by gravimetric analysis, and the morphology and composition of the corrosion products were obtained by Scanning Electron Microscopy with X-Ray Microanalysis (SEM-EDS) and X-Ray Diffraction (XRD) analysis respectively; showing similarity between the corrosion products thrown in the simulation. The gravimetric analysis showed that the corrosion rate of ASTM P5 steel was higher than in AISI 304 steel; it was explained because the no formation of an internal protective chromium oxide layer in ASTM P5 steel. On the other hand, the SEM-EDS analysis showed that the corrosion products formed on AISI 304 steel corresponded mainly to iron oxides and spinels. Unlike to the corrosion products obtained for ASTM P5 steel, for which only iron rich layers were formed. Additionally, the EDS analysis revealed carburization and sulfidation in both steels, although these effect were more representative on AISI 304 steel. Finally, the kinetic study suggested the formation of non-protective oxide layers, which was confirmed through SEM analysis; where were revealed cracks and gaps in the morphology of the oxide layers formed in both steels. Finally, it is important to mention that the methodology applied in this work is applicable to other steels in typical corrosive environments from the refinery's equipment.
