Chlorine corrosion of thermally sprayed coatings at elevated temperatures

摘要: This study compares the corrosion resistance of a wide range of coatings in a chlorine-containing atmosphere at elevated temperatures. Four HVOF-sprayed NiCr coating samples were produced and tested along with an iron-aluminide HVOF layer, a chromium diffusion layer, and a laser-treated HVOF NiCrMo layer. The investigators found that the structure of HVOF coatings has a major effect on corrosion resistance and that chlorine corrosion primarily attacks the substrate through cracks and interconnected networks of pores and oxides at splat boundaries. They also observed that laser melting increases corrosion resistance by homogenizing the coating structure. Paper includes a German-language abstract.