Superduplex stainless steel UNS S32750 / EN 1.4410 is commonly used in marine environment, petrochemical, oil and gas, chemical and desalination industries, requiring materials with superior corrosion and mechanical properties. Very few residual intermetallic particles may be present under the form of centerline stringers whose effects on corrosion properties are not well documented. A previous study demonstrated the negligible influence of the intermetallic phases in centerline stringers (typically < 0.1% over thickness) on the hydrogen embrittlement susceptibility of superduplex stainless steel [1]. The present study aims at highlighting the impact of centerline intermetallic stringers on pitting corrosion resistance. Samples containing σ-phase only within segregated centerline area have been intentionally produced in the laboratory. After detailed microstructural characterization, ASTM G48 Method A tests and long term immersion tests have been conducted to demonstrate that very few intermetallic phases within segregated bands don’t lead to a loss of pitting resistance. Then macroscopic and microscopic electrochemical investigations were performed on samples with centerline intermetallic stringers to highlight the weak points of microstructure regarding corrosion properties. © 2021 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 contentof the work lies solely with the author(s).1Paper No.16298Association for Materials Protection & Performance
Key words: DX2507, UNS S32750, 1.4410, intermetallic phases, centerline stringers, pitting corrosion resistance