Corrosion behavior of stainless steels was investigated in nitric acid for the effect of cold work, sensitization heat treatment and its combination. Corrosion rate of solution-treated Type 304 with extra low carbon (304ELC) increased with time and reached constant values after 1000 h of immersion time. Constant corrosion rates, however, were obtained for 25Cr-20Ni-Nb (310Nb) from the initial stage of immersion. Cold work mitigated corrosion of the solution-treated stainless steels. The effect of cold work was different on the two stainless steels with sensitization heat treatment, showing accelerated corrosion for 304ELC. The corrosion resistance of 310Nb was superior to 304ELC after all the treatments.

Chromium concentration of the sensitization treated 304ELC was lower in the grain-boundary region than that of the solution-treated one, although no chromium carbide precipitation was observed. This might be the cause of corrosion enhancement by sensitization treatment.

Subject
Materials, Acid concentration, Corrosion rate, Transmission electron microscopy, Constants, Nitric acid, Corrosion losses, Corrosion behavior, Sensitization, Carbon, Immersion, Stainless steel, Heat treatment
Keywords:
reprocessing, stainless steel, nitric acid, sensitization, inter-granular corrosion, trans-passive corrosion, cold work, dislocation, martensite
© 1997 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).
1997
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.