Orientation relationships of Laves phase and NiAl particles in an AFA stainless steel

摘要

The alumina- forming austenitic (AFA) stainless steel, Fe- 20Cr- 30Ni- 2Nb5Al (in at. %) was solutionized at 1250 degrees C in order to obtain a fully austenitic microstructure and then aged for up to 1325 h at 800 degrees C to precipitate the Laves phase and B2- NiAl particles typically found in AFAs. This paper describes detailed analyses of the orientation relationships between these particles and the matrix which were determined by transmission electron microscopy. Four variants of the (111) m//(0 0 0 1) p, [110] m//[1010] p orientation relationship proposed by Denham and Silcock (J. Iron Steel Inst. 207 (1969) p. 582) were observed for the Laves phase, and six variants of the (111)(m)//(011)(p),[101](m)//[111](p) Kurdjumov-Sachs relationship were observed for the B-2- NiAl phase.