Hot Corrosion of Aluminized 1020 Steel with NaCl Deposit

Abstract

The oxidation of hot-dip aluminized AISI 1020 steel coated with NaCl in static air at 700°C for a duration of time 49 h was studied by employing thermogravimetry, Scanning Electron Microscopy (SEM), Electron Dispersive Spectroscopy (EDS) and X-ray Diffraction (XRD) analysis. It was found that NaCl deposits markedly accelerated the oxidation of the AISI 1020 steel. The aluminide coating on the bare steel gives the best oxidation protection by forming continuous alumina scale (Al2O3). The degradation of aluminide layer and alumina scale on the steel are associated by chloridation/oxidation cyclic reactions. In addition, the released chlorine will be as catalytic actions and leads to the formation of loose Al2O3during corrosion.