Corrosion properties of chromia based eco - friendly coatings on mild steel

Abstract

Ceramic nanocrystalline coatings of chromium oxide (III) on steel S235JRH-1.0038 (EN 10025-1) were prepared using the liquid precursor plasma spraying (LPPS) method from ammonia dichromate (VI). Their structure and anti – corrosion properties were compared to the standard chromium oxide (III) coating prepared by thermal spraying. The newly prepared coatings had very high adhesion and minimal porosity. Anticorrosion properties were characterized by the means of the electrochemical impedance spectroscopy (EIS), measuring the charge transfer resistance Rct and capacitance of electrical double layer CPEdl in the 0,5 mol/l NaCl. Coatings of Cr2 O3 prepared by the LPPS method showed unambiguously improved anti - corrosion properties.

Keywords

• ceramic
• steel coating
• corrosion
• plasma spraying