The zinc-containing primers, especially zinc silicate, are widely used on the carbon steel for both onshore and offshore environments. Their use on stainless steels is not recommended since there is a risk of liquid metal embrittlement by molten zinc in case of fire due to its low melting point. Zinc silicate contains metallic zinc particles which can diffuse into the stainless steel if the particles melt. However, zinc quantity may not be sufficient (the thickness is 60 to 90 microns) to initiate a significant cracking. Also the oxidation of zinc particles, which are very small, before they reach melting temperature, would not permit cracking of stainless steels. In order to confirm these possibilities some tests were carried out on three types of stainless steels painted with 60 to 90 microns of zinc silicate and heated to temperatures 400 to 650°C. No cracking was observed on painted samples but cracking was experienced on stainless steel samples when a piece of zinc is placed on the stainless steel surface. This paper summarizes the test results and discusses the possible reasons of non-cracking.

Subject
Primers, Steel surfaces, Silicates, Liquid metals, Stress cracking, C ring stress corrosion testing, Zinc silicates, Specimen preparation, Zinc, Stainless steel, Cracks, Liquid metal embrittlement, Paints
Keywords:
liquid metal embrittlement, zinc silicate, stainless steel
© 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.