The effect of hydrodynamics on the corrosion of Zn and Al – 14 wt% Zn – 8 wt% Mg alloy in artificial seawater media at room temperature was studied in a rotating cylinder electrode (RCE), system under turbulent flow conditions. Five different rotation rates were studied: 0 (or stagnant conditions), 1000, 3000, 5000 and 7000 rpm. The corrosion rates were measured by linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS).

For the systems studied, corrosion potential, Ecorr becomes more positive with increasing RCE rotation rate. The effect of increasing the rotation rate is to increase the availability of oxygen at the surface, which in turn will polarize the corrosion reaction in the more noble direction.

The corrosion rate linearly increases with increasing velocity over the range of rotational rates studied. This reflects the fact that the rate of corrosion is controlled, at least in part, by the rate of mass transfer.

Subject
Galvanic anodes, Corrosion rate, Diffusion, Slopes, Turbulent flow, Zinc anodes, Cathodic polarization curves, Hydrodynamics, Mass transfer, Current densities, Cathodic current density, Risk reduction, Electrodes
Keywords:
aluminum alloy, flow, rotating cylinder electrode, seawater, zinc
© 2011 Association for Materials Protection and Performance (AMPP). All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise) without the prior written permission of AMPP. Positions and opinions advanced in this work are those of the author(s) and not necessarily those of AMPP. Responsibility for the content of the work lies solely with the author(s).
2011
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.