Multiple-stripe pattern formation of Cr-Rich and CrN-rich alternative layers in the plasma nitriding of Fe-14Cr alloys

Novi Granito, Tatsuhiko Aizawa, Hideyuki Kuwahara

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Formation of multi-stripe pattern with Cr-rich and CrN-rich alternative layers can be synthesized via the plasma nitriding for high-chromium steels. Corresponding to this multi-stripe formation in microstructure, the hardness value fluctuates even in the inside of plasma-nitrided layer. Key process parameter is holding temperature: this multi-stripe formation can be reproduced only in the middle range of temperature for 873 < T < 973 K. In the lower temperature, normal nitrided layer with constant CrN volume fraction and hardness value plateau, was observed even by using the same plasma-nitriding process. The number of stripes increases monotonically with the nitriding time. CrN-rich and Cr-rich layers reflect on the black - white sublayer in optical microscopy. The growth rate of nitriding front was far lower than that calculated from the diffusion coefficient of nitrogen; the growth of nitrided layer cannot be explained only by the nitrogen diffusion or by the Wagner's model. Precise microstructure analyses were made by XRD, EDX and XPS to investigate the solute Cr and CrN concentration distributions. They became periodic in the nitrided layer, corresponding to the multi-stripe formation. On the basis of these analyses, the difference of nitriding process is discussed with aid of numerical simulation.

Original languageEnglish
Title of host publicationInternational Surface Engineering Congress - Proceedings of the 1st Congress
Pages29-38
Number of pages10
Publication statusPublished - 2003 Dec 1
EventInternational Surface Engineering Congress - Proceedings of the 1st Congress - Colombus, OH, United States
Duration: 2002 Oct 72002 Oct 10

Publication series

NameInternational Surface Engineering Congress - Proceedings of the 1st Congress

Conference

ConferenceInternational Surface Engineering Congress - Proceedings of the 1st Congress
CountryUnited States
CityColombus, OH
Period02/10/702/10/10

    Fingerprint

Keywords

  • Automotive parts
  • Fe-Cr alloy
  • Plasma nitriding
  • Plasma surface treatment
  • Wear resistance

ASJC Scopus subject areas

  • Engineering(all)

Cite this

Granito, N., Aizawa, T., & Kuwahara, H. (2003). Multiple-stripe pattern formation of Cr-Rich and CrN-rich alternative layers in the plasma nitriding of Fe-14Cr alloys. In International Surface Engineering Congress - Proceedings of the 1st Congress (pp. 29-38). (International Surface Engineering Congress - Proceedings of the 1st Congress).