Applied Microscopy

Korean Society of Microscopy (한국현미경학회)
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A Strategy for Phase Identification of Precipitates in High Al-containing Austenitic and Ferritic Steels Using Electron Diffraction

  • Heo, Yoon-Uk (Graduate Institute of Ferrous Technology, Pohang University of Science and Technology)
  • Received : 2014.12.06
  • Accepted : 2014.12.19
  • Published : 2014.12.30
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Abstract

A strategy for phase identification of precipitates in high Al-containing austenitic and ferritic steels using electron diffraction (ED) is studied. Comparative studies of the various Al-containing precipitates (k-carbide, $Ni_3Al$, $Fe_3Al$, FeAl) show the similarities of crystal structure and lattice parameter. However, the slight differences of lattice parameter and structure display characteristic ED patterns (EDPs) which can be identified. $L1_2$ k-carbide and $Ni_3Al$ can be differentiated by the length of ${\rightarrow}_g$ (the reciprocal lattice vector), even though they show perfectly identical shapes of EDPs. $DO_3$ $Fe_3Al$ and $B_2$ FeAl show the characteristic EDs in [110] and [112] beam directions due to the differences of Fe site occupancies in unit cells. k-carbide, $Ni_3Al$, and FeAl show also the similar EDs in [112], [112], and [110] beam directions, respectively. All the possible similarities of EDs among each phases and the strategy for phase identification are discussed on the bases of kinematical ED simulation.

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References

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