The Journal of
the Korean Journal of Metals and Materials

The Journal of
the Korean Journal of Metals and Materials

Monthly
  • pISSN : 1738-8228
  • eISSN : 2288-8241

Editorial Office

Title Effect of χ Phase Formation on the Mechanical Properties of 25Cr-7Ni-4Mo-0.2N Super Duplex Stainless Steel
Authors 강창룡(Chang Yong Kang); 김재환(Jae Hwan Kim)
DOI https://doi.org/10.3365/KJMM.2011.49.3.197
Page pp.197-202
ISSN 1738-8228(ISSN), 2288-8241(eISSN)
Keywords super duplex stainless steel; impact toughness; χ phase; σ phase
Abstract This study was carried out to investigate the precipitation behavior of χ phase and effect of χ-phase which precipitated at the initial stage of aging on mechanical properties of 25%Cr-7%Ni-4%Mo-0.2%N super duplex stainless steel. χ-phase was precipitated mainly at the interface of ferrite/austenite phases and inside of the ferrite phase at the initial stage of aging, and it was transformed into σ-phase with an increase of aging time. The ferrite phase was decomposed into new austenite(γ2)phase and σ-phase by aging treatment. The hardness and tensile strength of the initial stage of aging when χ-phase was precipitated did not changed considerably, while elongation rapidly decreased. Accordingly, it is considered that χ-phase didn`t affect the hardness and strength significantly, but it affected the elongation.