Rotating compressors have been used for many years to compress gas containing H2S in the Oil and Gas industry. For H2S service, the ISO 15156/MR0175 Standard describes the conditions for which metallic materials and particularly corrosion resistant alloys can be used. For martensitic stainless steels, there are no environmental constraints for compressor components although for impellers they must be resistant to sulfide stress cracking up to 95% of their actual yield strength. In the Lacq plant located in the south-west of France, good service has been obtained with compressor fit with 16%Cr 4%Ni martensitic stainless steel impellers for more than 20 years. Hence, it was a surprise when a failure occurred in one of the compressors in 2004. This paper describes the circumstances of this failure and the investigation carried out to understand its root cause. The consequences and thoughts concerning the use of martensitic stainless steels for compressor impellers are discussed.

Subject
Water, Materials, Compression, Crack initiation, Fracture surfaces, Stress cracking, Stress, Mechanical failure, Erosion, Sulfide stress cracking, Chlorides, Heat treatment, Martensitic steel
Keywords:
hydrogen sulfide, martensitic stainless steel, sulfide stress cracking, chloride, compressor impeller
© 2006 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).
2006
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.