Corrosion tests were carried out on C-steel (API 5L X70) and 13Cr steel (AISI 420) materials in a 3% NaCl solution containing sand particles (5000-9000 ppm) and saturated with CO2 at defined partial pressure (0-0.3 MPa) and temperature (30- 60°C). The effect of residual O2 content (10-1500 ppb) was further examined.

Two flow geometries were studied: 1) undisturbed pipe flow and 2) submerged jet impinging (30-90°) onto a flat plate. The effect of specimen surface treatment (shot-blasting or pickling) was examined with dry polished material as a reference. Weight-loss and electrochemical measurements were applied to determine average and instantaneous corrosion rates respectively.

The results are discussed in relation to fluid flow conditions and the surface preparation/microstructure of materials tested. No stable corrosion product layers retarding CO2 corrosion were formed within the testing time-frame. (<100 h). Consequently no erosion-corrosion associated with physical degradation of protective layers occurred. Enhanced corrosion of C-steel specimens has been related to the induced plastic deformation and disruption of the metal surface layer stimulating corrosion attack.

Subject
Wear, Water, Materials, Piping, Sand, Corrosion rate, Flow velocity, Partial pressures, Corrosion attacks, Fluids, Steel, Oxygen, Linear polarization resistance
© 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)
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