Internal boiler corrosion leads to the formation of magnetite and hydrogen. This process occurs naturally even when operating conditions are designed to minimize corrosion. However, conditions can occur which accelerate this reaction resulting in severe metal wastage. This is of special concern when localized attack occurs as in underdeposit corrosion. In general, the rate and type of corrosion can be identified by measuring and monitoring dissolved hydrogen in condensed steam samples.

Hydrogen studies are a useful method for predicting on-line boiler corrosion. The proper use of this technique can identify conditions which are occurring so that modifications in mechanical operation and chemical treatment programs can be made.

This paper summarizes the reactions involved in generating hydrogen and discusses the major chemical and mechanical parameters which influence corrosion in the boiler. Case studies are presented which focus on caustic attack and the decomposition of other materials which may influence the generation of hydrogen.

Subject
Decomposition, Alkalinity, Hydrogen concentration, Hydrazine, Metal surfaces, Iron, Feedwater, Boilers, Magnetite, Steam, Chemical reactions, Hydrogen, Types of corrosion
© 1990 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).
1990
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.