Phase transformations in duplex stainless steels: Metallographic and magnetic investigation

Calliari Irene, Breda Marco, Ramous Emilio, Meszaros Istvan

Research output: Contribution to journalArticle

Abstract

Heat treatment and cold working-induced microstructural processes were studied by metallography and different non-destructive magnetic in commercial lean, duplex(DSS) and superduplex stainless steels(SDSS). In DSS and SDSS, the metastable ferrite can decompose to a σ phase and secondary austenite due to heat treatment. All the mechanical, corrosion resistance and magnetic properties are strongly influenced by this microstructural changes. The capabilities of magnetic measurements allow a quantitative correlation between measured harmonics and mechanical properties obtained from destructive tests. In lean duplex, the substitution of Ni by N and Mn in lean grades may result in austenite phase instability, and this phase tends to transform to metastable martensite, while the SDSS auistenite could be more stable. The plastic deformation of the solution annealed materials was carried out by RT cold rolling (10%-85%T. R.). The 2101 was examined only in rolled condition while the cold rolled 2507 samples were also heat treated. The cold rolled samples were examined with OM, SEM, XRD and magnetic measures. Three different magnetic tests were applied for determining the magnetic behaviour of DSS samples. The effect of cold rolling is on grains size and shape and the magnetic tests suggest the martensite presence in 2101.

Original languageEnglish
Pages (from-to)10-15
Number of pages6
JournalYejin Fenxi/Metallurgical Analysis
Volume33
Issue number7
Publication statusPublished - Jul 1 2013

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Keywords

  • Lean duplex
  • Magnetic tests
  • Martensite
  • Phase transformation

ASJC Scopus subject areas

  • Metals and Alloys
  • Materials Chemistry

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