Published online by Cambridge University Press: 26 February 2011
The discontinuous grain boundary (GB) precipitation behavior of rapidly solidified Fe-31.3wt. % Mn-8.7wt.%A1-2.0wt.%C on aging at 923K has been investigated by TEM and X-ray diffraction. The parent matrix was already composed of fcc ɣ phase and perovskite K' carbide of L'12 crystal structure even before the aging treatment. On aging, the matrix precipitation of K' phase out of the -ɣ-phase matrix progressed further, but eventually came to a standstill before the initiation of the DP reaction in the GB. Later on, cells or colonies made up of alternate lamellae of carbon depleted ɣ and carbon enriched K phases of L'12 structure continued to grow. Between the product ɣ and K phases in a cell, near perfect {111} interfaces were found.