Matrix analysis on Isaichev orientation relationship

By means of TEM technique the orientation relationships of cementite, precipitated from islands of granular bainite during tempering, with ferrite have been observed. By calculating the eigenvalue and eigenvector of transformation matrix, Isaichev relationship has been analyzed. The results indicate that Isaichev relationship indeed is the sum of Kurdjumov-Sachs relationship and Pitsch relationship, so the viewpoint that the cementite with Isaichev relationship precipitates from austenite, in stead of ferrite, is confirmed. Moreover, the matrix calculation shows that three reported orientation relationships among austenite, ferrite and cementite in pearlitic transformation cannot be simultaneously valid