Enhanced corrosion protection performance using polysilazane-derived amorphous SiCN ceramic coating

In this work, a polymer-derived silicon carbonitride (SiCN) ceramic layer has been deposited on stainless steel 304 (SS304) to enhance the corrosion resistance of SS304 in a seawater environment. SS304 is dip-coated with a polysilazane solution followed by pyrolysis under argon environment at 800( degrees)C to develop SiCN ceramic layer with a thickness of about 3 mu m on SS304. Structural characterization of the prepared samples was performed using Fourier transform infrared (FTIR), X-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM). Potentiodynamic polarization tests of SS304 and SiCN-coated SS304 were performed in 0.6 M NaCl solution. SiCN-coated SS304 showed very low corrosion current density of 4.2 x 10(-10) A/cm(2) whereas corrosion current density of uncoated SS304 was measured to be 1.52 x 10(- 7) A/cm(2). Excellent corrosion resistance performance of SiCN-coated SS304 was observed as confirmed by electrochemical impedance spectroscopic (EIS) measurements.