Extension of the Life Time of Thin Foils Made of Fe-Cr-Al Alloys

  1. Dr. P. J. Winkler
  1. J. Klöwer1,
  2. A. Kolb-Telieps1,
  3. V. Kolarik2 and
  4. M. Juez-Lorenzo2

Published Online: 23 DEC 2005

DOI: 10.1002/3527606025.ch18

Materials for Transportation Technology, Volume 1

Materials for Transportation Technology, Volume 1

How to Cite

Klöwer, J., Kolb-Telieps, A., Kolarik, V. and Juez-Lorenzo, M. (2005) Extension of the Life Time of Thin Foils Made of Fe-Cr-Al Alloys, in Materials for Transportation Technology, Volume 1 (ed P. J. Winkler), Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, FRG. doi: 10.1002/3527606025.ch18

Editor Information

  1. DaimlerChrysler AG, Forschung und Technologie, Postfach 800 465, 81663 München, Germany; Tel.: 089–607 22393; Fax: 089–607 28627

Author Information

  1. 1

    Krupp VDM, Werdohl, Germany

  2. 2

    Fraunhofer-Institut für Chemische Technologie (ICT), Pfinztal, Germany

Publication History

  1. Published Online: 23 DEC 2005
  2. Published Print: 20 APR 2000

Book Series:

  1. EUROMAT 99

ISBN Information

Print ISBN: 9783527301249

Online ISBN: 9783527606023

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Keywords:

  • transportation technology;
  • materials;
  • automotive applications;
  • thin foils of Fe-Cr-Al alloys;
  • life time extension

Summary

Foils of Fe-20Cr-Al alloys are widely used as substrates in metal-supported automotive catalytic converters. Law tightening in exhaust emission standards in Europe and California within the next years, however, requires higher efficiency of the catalysts providing the demand for new catalytic converter designs. This includes a reduction of the foil thickness from currently 50 µm to 30 µm. To avoid disadvantages in the oxidation resistance, the aluminum content of the substrate alloys was increased from 5 wt% to 7 wt% and the additions of reactive elements were adjusted in order to improve adherence and density of the oxide scale.

The oxidation behavior of the prototype alloys Fe-20Cr-7Al Y Hf and Fe-20Cr-7Al Y Zr Ti was studied in situ by high temperature X-ray diffraction. Isothermal experiments of 100 hours were performed in air at 1000 and 1100°C with a subsequent electron microprobe analysis. The results show the influence of the reactive element additions leading to the conclusion that the reactive element composition and concentration of the prototype alloy Fe-20Cr-7Al Y Hf provides a better oxidation resistance than that of alloy Fe-20Cr-7Al Y Zr Ti. While the alloy Fe-20Cr-7Al Y Hf forms alumina only, the additional oxides MnAl2O4 and ZrO2 were observed on Fe-20Cr-7Al Y Zr Ti.