Abstract: Based on the empirical electron theory of solids and molecules founded by Yu R.H.Austenitic structure of industry alloys was analyzed from bond length difference (BLD) method. And combined with obtained information of valence electron structure of the materials, the following viewpoint was advanced:1.There are concentration regions of C -Me in austenite of Fe-C-Me alloys.2.C-Me concentration is of resistance on phase transformation, the mutual action of this resistance and driving force of phase transformation affects the structure and the properties of the products of phase transformation.3. From C-Me concentration viewpoint, new explainaticn was proposed for a few problems of metallography: (1)The form of retained austenite. (2)The incompleteness of bainitic transformation of some alloy steels and bainite morphology variation. (3)The formation of both dislocation and twin martensite.

Key words: 材料, 相变, 余氏理论, Actuation singularity, Dead point, Screw theory, Vertical Darboux motion, Spatial single-loop mechanism