An investigation of accelerated atmospheric corrosion of copper by using a four-point-probe method and the Scanning Electron Microscope (SEM) is described. An aggressive atmosphere containing 100 ppm of H2S and a relative humidity (RH) above 80% was used to accelerate the corrosion process under a controlled environment. The test consisted of two containers testing, in triplicate, 25μm thick copper wire. The inhibited samples showed less increases in the measured voltage than the specimens not inhibited. The decrease in the voltage could be correlated to the corrosion rate and the efficacy of the VCI. The SEM images revealed different surface changes in the oxide formation on the protected and non-protected copper surface. We expect that this test presents a possible alternative to existing test methods, i.e. Japanese and German based on the commonly used Federal Test Method 4031, 101C a.k.a. Vapor Inhibiting Ability of VCI Vapors (VIA). Both the VIA test and this test are quite simple to conduct, however, this test represents the corrosion quantitatively which is not possible with the VIA.

Subject
Scanning electron microscopy, Test methods, Water, Materials, Voltage, Glass, Containment, Wiring, Rods, Volatile corrosion inhibitors, Surfaces, Corrosion inhibitors, Copper
Keywords:
Volatile Corrosion Inhibitor, VCI, H2S, relative humidity, Vapor Inhibiting Ability, copper, SEM, four-point-probe, voltage
© 1999 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).
1999
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.