  The forward transformation from face centered cubic austenite to body
centered cubic/tetragonal martensite in ferrous alloys can significantly in-
fluence the microstructure and mechanical properties of the material. Inferring
possible high temperature crystal orientations from observations of ambient
temperature transformation microstructures is hindered by parent austenite-
twin interactions and scatter in the orientation relationship. This creates a
major limitation for studying variant selection phenomena and characteriz- ing
microstructural response to high temperature thermomechanical process- ing
conditions. In this work, composition tables are developed that detail the
product variant boundary misorientation relationships for parent-parent,
parent-twin and twin-twin boundary intersections for the Kurdjumov-Sachs (KS),
Nishiyama-Wassermann (NW), and an experimentally determined irra- tional
orientation relationship. The frequently referenced KS and NW ori- entation
relationships produce significantly different results from experimental
observations. Furthermore, the introduction of a twin into the parent austenite
introduces a substantially larger number of misorientation relationships when
the orientation relationship is irrational. The effects of crystal symmetry on
misorientation results are determined by considering both body centered cu- bic
and body centered tetragonal martensite structures. Lastly, it is observed that
some shared variants are found between twins and parents when assuming cubic
symmetry but not tetragonal symmetry. The results and relationships may be
useful towards accurate and consistent reconstructions of the parent austenite
microstructure from observations of martensite.
