研究論文
亜鉛めっき皮膜上へのセリウム含有化成処理皮膜の作製と耐食性評価
2004 年 55 巻 4 号 p. 276-280
詳細
2004 年 55 巻 4 号 p. 276-280
The possibility of cerium conversion coating has been studied as a replacement for chromate-based coating treatment on electroplated zinc on galvanized steel. The deposition of cerium (hydro)oxide film was carried out by a simple immersion into an aqueous solution of cerium(III) chloride, nitrate, sulfate, and acetate at ambient temperature. The morphorgy, composition and corrosion resistance were examined by atomic force microscope, X-ray photoelectron spectroscopy, and salt spray test, respectively. The Ce-film had a thickness up to 100nm, and had granular structure below 100nm in size. The result of salt spray test showed that Ce-film obtained from cerium sulfate solution has a higher corrosion resistance than that obtained from other cerium salts solutions. In the case of Ce sulfate solution, the sulfate anion was incorporated from immersion solution into the film. The corrosion resistance of Ce conversion coating is not improved by the morphorgy of the Ce film, but by the existence of the sulfate ion in the Ce film.
