Electrochemical Characterization of Plasma Sprayed Alumina Coatings

• 作者: Akira KOBAYASHI Ivan COLE Magdi. F. MORKS Penny Corrigan
• 来源期刊: 表面工程材料与先进技术期刊(英文)
• 学科: 工学
• 关键词: Plasma SPRAYING ALUMINA Coating MILD Steel Corrosion POLARIZATION EIS
• 年，卷（期）: bmgcclyxjjsqkyw_2011,（3）
• 页码范围: 107-111
• 页数: 5页
• 分类号: TG17

摘要

Open circuit potential (OCP), potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) were employed to characterize the corrosion behavior of plasma-sprayed alumina-coated mild steel in 3.5 wt% NaCl solu-tion. Alumina-coated steel showed higher OCP and lower corrosion current (icorr.) compared with the steel substrate. However, localized corrosion probably occurs at the coat/steel interface when immersed in the corrosive media. The reason for that is the penetration of corrosive solution into the steel surface through the pores of accumulated alumina layers. The corrosion products (mainly iron oxides) accumulate inside the pores and on the coating surface. The presence of iron oxide slightly improved the corrosion resistance.