The effect of galvanic coupling of some experimental ELI superferritic stainless steels with some less noble metallic materials was evaluated in synthetic sea water under constsnt strain rate conditions. Times to failure of the stainless steels are markedly shortened by coupling with Zn, Al + 4% Zn and Mg, being the corrosion potentials shifted down to the potentials where hydrogen evolution occurs. Coupling with more noble metallic materials like Admiralty brass does not effect the stress-strain behaviour and ductile fracture occurs. Coupling with Armco iron does not effect the stress-strain behaviour but SEM fractographs indicate the occurrence of hydrogen up-take. Evidence of hydrogen embrittlement at potentials ranging -0.7V s.c.e. was also found on uncoupled specimens under potentiostatic control. Maximum care must be taken for galvanic coupling and cathodic protection of these stainless steels,leading to corrosion potentials at -0.7V s.c.e. or below.

Subject
Noble potential, Water, Materials, Stainless alloys, Nickel based alloys, Couplings, Iron, Mechanical failure, Zinc, Stainless steel, Fracture, Mixed potential, Corrosion potential
© 1986 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).
1986
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.