Abstract: Some characteristics of plate martensite in a 1.03% C ferroalloy have been studied by using the transmission electron microscopy.The habit plane of the plate martensite in this ferroalloy was found to be close to{224}_f.The morphology,distribution,coalescence and curving of martensite as well as the substructure in both martensite and austenite have been observed. The mechanism of both nucleation and growth of the martensite have been discussed.

Key words: high-carbon ferroalloy, martensite, substructure, habit plane, nucleation