The effect of water in a methanol solution containing 0.42 wt% LiCl on the corrosion behavior of type 316L stainless steel was evaluated by anodic polarization and electrochemical impedance spectroscopy (EIS) at 423K and 473K. The addition of water to the methanol solution increased the anodic dissolution potential (Ea) at both temperatures. At 423K, an increase in the corrosion potential (Ecorr) was observed and the passive region was reduced by the addition of even small amounts of water. The specimen surface structure after anodic polarization measurements changed from a localized tarnish to pitting with an increase in the amount of added water. A random plot of electrochemical impedance spectroscopy (EIS) results showed typical pitting corrosion at an initial stage caused by an autocatalytic process. The water impurity increased the risk of chloride attack at 423K. Corrosion was activated as the added water volume increased. At 473K, no corrosion occurred, regardless of the water concentration.

Subject
Electrochemical impedance spectroscopy, Water, Passive films, Anodic polarization curves, Anode surfaces, Nyquist plots, Mixtures, Solutions, Immersion, Corrosion resistance, Methanol, Anodic polarization, Corrosion potential
Keywords:
methanol, anodic polarization, electrochemical impedance spectroscopy, corrosion
© 2009 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).
2009
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.