Corrosion fatigue crack growth rates of a quenched and tempered Type 403 stainless steel have been measured in concentrated sodium hydroxide and sodium chloride solutions with and without the addition of sodium silicate and sodium phosphate as potential inhibitors using compact tension specimens (CTS). All tests were performed at 100°C with a sinusoidal loading wave form at R=0.5 and at frequencies of 0.1, 1, and 10 Hz. Tests in air were also conducted to obtain the base line data for fatigue crack growth rates (FCG).

At open circuit potentials, corrosion fatigue crack propagation rates were highest in concentrated sodium chloride solution. The environmental enhancement of fatigue crack growth became more evident as the frequency was decreased in both 10 mol kg−1 (m) sodium hydroxide and saturated (6.6 mol kg−1) sodium chloride solutions.

Both sodium phosphate and sodium silicate at the concentrations used in this work showed no beneficial effect on the corrosion fatigue crack growth rates for Type 403 stainless steel in 10 mol kg−1 NaOH solution.

However, the addition of sodium silicate and sodium phosphate showed inhibiting effects in 6 mol kg−1 sodium chloride solution. The inhibiting actions of these compounds were strongly concentration dependent. A crack growth rate equivalent to that in air was found with the addition of 0.5m Na3PO4 or 0.5m Na2SiO3.

Subject
Crack growth, Corrosion fatigue, Corrosion rate, Silicates, Sodium chloride, Fatigue crack growth rate, Sodium chloride solution, Phosphates, Sodium, Salt concentration, Corrosion inhibitors, Sodium hydroxide, Corrosion potential
© 1982 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).
1982
Association for Materials Protection and Performance (AMPP)
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