An 18R martensite phase was observed in the body-centered cubic matrix of this alloy after cooling from high temperatures. The martensite was orthorhombic, with lattice constants of a = 0.448nm, b = 0.259nm and c = 3.865nm, and could be described as having a (42)3 structure rather than a (51)3 structure. The calculated crystallographic details agreed with the experimentally observed crystallography. The Burgers vector of the anti-coherency dislocations and shape strain directions were confirmed by using the 2-beam technique and computer image simulations. Further analysis suggested that the (42)3 interface was energetically more favorable than the (51)3 interface.

W.B.Lee, F.R.Chen, C.M.Wan: Materials Science Forum, 1995, 189-190, 241-8