Corrosion behavior of TiO2-treated type 304 stainless steels in high temperature water containing with hydrogen peroxide

ABSTRACT Titanium dioxide (TiO2) treatment coupled with ultraviolet irradiation was selected as a corrosion mitigation technique for Type 304 stainless steel (SS) in high-temperature pure water with the presence of hydrogen peroxide (H2O2). Type 304 SS specimens were pre-oxidized in oxygenated pure water at 288 °C and then coated with TiO2 nanoparticles by hydrothermal deposition. Electrochemical polarization analyses were conducted to investigate the corrosion behavior of both TiO2-treated and pre-oxidized specimens in 288 °C pure water with 300 ppb H2O2. Ultraviolet (UV) irradiation was then imposed upon the TiO2-treated specimens to examine if there was any distinct photoelectric effect on the corrosion behavior of the treated samples. It was found that the electrochemical corrosion potentials of the TiO2 treated specimens under UV irradiation were 10–20 mV lower than those without UV. In addition, the corrosion current densities of the treated specimens were also lower in the presence of UV radiation. Without UV radiation, however, no significant differences were observed between the TiO2 treated and untreated specimens. These results indicate that the TiO2 treatment in combination with UV radiation would reduce the corrosion rate of Type 304 SS in H2O2-rich, high-temperature pure water.