Electrochemical passive properties of AlxCoCrFeNi (x=0, 0.25, 0.50, 1.00) alloys in sulfuric acids
2009; Elsevier BV; Volume: 52; Issue: 3 Linguagem: Inglês
10.1016/j.corsci.2009.11.028
ISSN1879-0496
AutoresYih-Farn Kao, Tsung-Dar Lee, Swe-Kai Chen, Yee-Shyi Chang,
Tópico(s)Corrosion Behavior and Inhibition
ResumoThis study investigates the electrochemical passive properties of AlxCoCrFeNi alloys in H2SO4 by potentiodynamic polarization, EIS, and weight loss tests from 20 to 65 °C. Experimental results indicate that Al harms the corrosion resistance in H2SO4 at temperatures exceeding 27 °C owing to the porous and inferior nature of the protection oxide film of Al in these alloys. Closely examining the Arrhenius plots of corrosion current density reveals that both pre-exponential factor A and activation energy Ea increase with Al content. However, A affects corrosion current density more significantly than Ea at higher temperatures and, conversely, at lower temperatures.
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