Corrosion resistance of duplex stainless steel has been studied with particular attention to pitting corrosion and stress corrosion cracking. Pitting corrosion resistance was established by immersion test in ferric chloride solution and pitting potential measurement in chloride, hydrogen sulfide environments. The corrosion potential is always less noble than the pitting potential and the difference between the two potentials becomes smaller with lowering of pH, and with increasing of the H2S partial pressure, temperature and chloride concentration. Similar to the base metal, pitting corrosion resistance of the weldment depends on its chemical composition or pitting index, but a pitting index of high value is required to obtain satisfactory resistance. Resistance to stress corrosion cracking is affected by the partial pressure of H2S and the stress level but not by temperature and welding. The critical partial pressure of H2S at 1.0 Y.S. is 0.02 atm and the threshold stress at higher partial pressure of H2S is 0.6 Y.S.

Subject
Noble potential, Materials, Sodium chloride, Partial pressures, Acidity, Stress, Welded joints, Sodium chloride solution, Pitting, Corrosion resistance, Chlorides, Corrosion potential, Stress corrosion cracking
© 1987 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).
1987
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.