The so-called oxyfuel process is frequently considered as a promising technology for CO2 capture from the exhaust gas in fossil fuel fired power plants. In the present paper, the oxidation behavior of potentially suitable construction materials for heat exchanging components in coal fired power plants was studied at 650°C. The selected materials (martensitic steels, austenitic steels and a Ni-base alloy) were exposed in a simulated atmosphere typical for oxyfuel combustion and the results were compared with the behavior in a test gas simulating air-firing flue gas. Additionally a set of corrosion tests was performed in the simulated oxyfuel gas with addition of CO to simulate locally occurring reducing operating conditions.

The oxidation/corrosion behavior was studied by gravimetry in combination with a number of characterization methods such as optical microscopy, scanning electron microscopy with energy dispersive x-ray analysis (SEM/EDS) and (for selected specimens) glow discharge optical emission spectroscopy (GDOES), x-ray diffraction (XRD) and electron backscatter diffraction (EBSD). The obtained results are interpreted on the basis of thermodynamic considerations comparing equilibrium activities of the main species in the gas atmospheres with the thermodynamic stabilities of various possibly forming solid and volatile corrosion products.

Subject
Sulfur, Materials, Corrosion rate, Nickel based alloys, Oxide formation, Sulfates, Metallography, Oxide scales, Scale formation, Steel, Oxygen, Gases, Oxidation
Keywords:
Oxyfuel combustion, oxidation, corrosion, ferritic, martensitic steels, austenitic steels, nickel base alloy
© 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.