Corrosion behaviour of carbon S-phase created on Ni-free biomedical stainless steel

D Formosa, R Hunger, A Spiteri, Hanshan Dong, E Sinagra, J Buhagiar

Research output: Contribution to journalArticle

16 Citations (Scopus)


Following the success of forming a carbon S-phase (expanded austenite) surface layer on medical grade Ni-free austenitic stainless steel by DC plasma carburising, the established commercial carburising process Kolsterising (R) was performed on both Ni-containing (AISI 304) and Ni-free austenitic stainless steels. While the Ni-containing stainless steel responded very well to Kolsterising (R), the Ni-free alloy did not. The carbon absorption and the hardness of the Kolsterised (R) Ni-free alloy are inferior to Kolsterised (R) AISI 304 Ni-containing stainless steel, however, the hardness of the untreated Ni-free alloy was doubled by Kolsterising (R). The response of both Kolsterised (R) Ni-free and Ni-containing alloys to pitting, crevice corrosion and intergranular corrosion resistance was similar. From this work it can be concluded that the Kolsterised (R) austenitic stainless steels do not suffer from intergranular corrosion but are susceptible to intragranular pitting when tested in boiling sulphuric acid and copper sulphate solution. It was also observed that Kolsterising (R) improves significantly the pitting and crevice corrosion resistance of the alloys used in this study. (C) 2012 Elsevier B.V. All rights reserved.
Original languageEnglish
Pages (from-to)3479-3487
Number of pages9
JournalSurface and Coatings Technology
Issue number16
Publication statusPublished - 1 Apr 2012


  • S-phase
  • Nickel free austenitic stainless steel
  • Intergranular corrosion
  • Kolsterising
  • Expanded austenite
  • Crevice and pitting corrosion


Dive into the research topics of 'Corrosion behaviour of carbon S-phase created on Ni-free biomedical stainless steel'. Together they form a unique fingerprint.

Cite this