Detection of secondary phases in duplex stainless steel by magnetic force microscopy and scanning Kelvin probe force microscopy

J. Ramírez-Salgado, M. A. Domínguez-Aguilar, B. Castro-Domínguez, P. Hernández-Hernández, R. C. Newman

Research output: Contribution to journalArticle

12 Citations (Scopus)


The secondary phase transformations in a commercial super duplex stainless steel were investigated by micro-chemical analyses and high resolution scanning probe microscopy. Energy dispersive X-ray and electron probe detected ferrite and austenite as well as secondary phases in unetched aged duplex stainless steel type 25Cr7Ni3Mo. Volta potential indicated that nitride and sigma appeared more active than ferrite, while secondary austenite and austenite presented a nobler potential. Reversal order in nobility is thought to be attributable to the potential ranking provided by oxide nature diversity as a result of secondary phase surface compositions on steel. After eutectoid transformation, secondary austenite was detected by electron probe microanalysis, whereas atomic force microscopy distinguished this phase from former austenite by image contrast. Magnetic force microscopy revealed a "ghosted" effect on the latter microstructure probably derived from metal memory reminiscence of mechanical polishing at passivity and long range magnetic forces of ferrite phase.

Original languageEnglish
Pages (from-to)250-262
Number of pages13
JournalMaterials Characterization
Publication statusPublished - 14 Nov 2013


  • Atomic force Microscopy (AFM)
  • Electron Probe Microanalysis (EPMA)
  • Intermetallics
  • Magnetic force microscopy (MFM)
  • Scanning Kelvin probe force microscopy (SKPFM)

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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