Corrosion immersion tests of 3%Cr steel and API X65 pipeline steel were carried out in the high-pressure high-temperature autoclave, in order to simulate the typical corrosion environment of oil and gas transported pipeline. The effects of temperature and CO2 partial pressure on corrosion behaviors were investigated, and the purpose of this paper was to compare the corrosion resistance of 3%Cr steel with API X65 pipeline steels in CO2 corrosion environment.

The results show that, the corrosion of both 3%Cr steel and API X65 pipeline steel were slight in mild corrosion environment, so we could choose API X65 steel in these environment. With temperature or CO2 partial pressure increasing, the corrosion resistance of 3%Cr steel was superior to API X65 pipeline steel. The analysis of composition and morphology revealed that the corrosion product film of 3%Cr steel was composed of FeCO3, Cr(OH)3 and Cr2O3. An amorphous scale without grain boundaries and pores was formed on the surface of 3%Cr steel due to the Cr element enrichment, which offered considerable resistance to corrosive medium, therefore the corrosion rate was decreased and local corrosion was inhibited.

Subject
Scanning electron microscopy, Films, Pipe surfaces, Steel surfaces, Materials, Corrosion rate, Pipelines, Partial pressures, Corrosion products, Corrosion morphology, Steel, Corrosion resistance, Elements
Keywords:
3%Cr steel, API X65 pipeline steel, temperature, CO2 partial pressure, corrosion rate, corrosion product film
© 2011 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).
2011
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.