2009 Volume 49 Issue 3 Pages 425-430
Different corrosion mechanisms and their extent within a sinter plant gas pipeline were studied. The low temperature-high moisture at the charging side and high temperature-low moisture at the discharging side exist in the main gas pipeline. The waste gas velocity is maximum near charging side and minimum near discharging side. Aggressive conditions near the charging side resulted in faster corrosion than the discharging side. The electrochemical effect was predominant at the wall while erosion effect was significantly higher at the center of the pipe. The overall effect however turns out to be same at wall and center for a particular location of the pipeline. This has been attributed to the velocity effect of waste gases.
The corrosion products were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction XRD techniques. The low temperature-high moisture at the charging side promotes electrochemical reaction with formation of bigger goethite and hematite. Only, hematite was detected in between charging and discharging side where as different iron oxides and alkali compounds were detected near the discharging side.