Crystallographic characteristics of stress-assisted martensite

X-ray diffraction of austenite single crystals of a steel Fe-18% Ni-0.8% C was used to determine the orientation relationship between the crystal lattices of austenite and martensite formed under the action of elastic stresses near the temperature of the onset of martensite transformation. This orientation relationship is independent of the orientation of the applied stresses and corresponds to the Greninger-Troiano relationship. Under the stresses applied in the considered crystallographic orientations, at most four variants of martensite orientation and their three or four twins over the (112)(alpha)(111)(alpha) system are realized instead of 24 possible ones.