The susceptibility to hydrogen embrittlement (HE) of an ultra-high strength Corrosion Resistant Alloy (CRA) OCTG was evaluated. A high-strength nickel alloy OCTG with 140ksi (965MPa) grade has been newly developed for use in high temperature and high pressure corrosive wells. This new alloy has exhibited equivalent stress corrosion cracking resistance to UNS(1) N08535 with conventional 110ksi (758MPa) grade. The strength of the material was enhanced by alloying nitrogen and cold working. In this study, the galvanically induced hydrogen stress cracking (GHSC) susceptibility was evaluated in sour environments by galvanically coupled type constant-strain or sustained-stress tests with carbon steel. Another evaluation method using slow strain rate testing (SSRT) under cathodic charging condition was employed to determine the hydrogen embrittlement (HE) susceptibilities of the different alloys tested including the developed alloy. It is revealed that the resistance to HE of the developed alloy is superior to other CRAs such as type 304L and some precipitation hardened alloys. From the results obtained, it can be considered that the high stability of austenitic phase, proper cold working ratio and no significant precipitation in this alloy achieve the excellent resistance to HE.

Subject
Hydrogen embrittlement, Tubular goods, Materials, Dislocation, Hydrogen concentration, Hydrogen content, Nickel based alloys, Sodium chloride solution, Fracture, Alloys, Heat treatment, Aging, Hydrogen
Keywords:
CRA, Hydrogen Embrittlement, Sulfide stress cracking, High Strength, Cold Work, Precipitation hardening, Chromium, Nickel, Nitrogen, Hydrogen sulfide
© 2016 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).
2016
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.