Numerical simulations were conducted to understand the behaviour of sacrificial aluminium coatings obtained by arc spray with varying areas of damage and its capacity to polarise the steel under a simulated marine environment. The damage tolerance of a 300 μm thick coating of aluminium alloy AA 1050 (TSA) with 5%, 20%, 50% and 90% exposed steel surfaces was evaluated in a time-dependent model. Arbitrary Lagrangian Eulerian (ALE) was used in a moving mesh technique to simulate the consumption of the TSA coating surface. Cathode surface, in this case, exposed steel, is assumed non-deforming in the model. The simulations were compared with experimental measurements of open circuit potential (OCP) and corrosion rate (CR) from previous studies, where the electrochemical behaviour of TSA with exposed steel surface was evaluated over different periods of time in artificial seawater at 20°C. The corrosion rates obtained using the model are in broad agreement with those estimated from laboratory experiments. In addition, the model predicted sacrificial protection offered by TSA coating as a function of the exposed steel.

Subject
Steel surfaces, Modeling, Cathodic protection, Geometry, Corrosion rate, Aluminum spraying, Aluminum, Coating damage, Corrosion modeling, Steel, Protection potential, Electrolytes, Electrode potential
Keywords:
Thermal spray coating, cathodic protection, marine environments, simulations and modelling
© 2022 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 (OR NACE OR SSPC). Responsibility for the content of the work lies solely with the author(s).
2022
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.