Formation Mechanism 上濟充通大学 Transformation temperature:(>Ac) Phases: a Fe3C → Compositions (wt%):0.02% 6.7% 0.77% Crystal structures: BCc Orthorhombic FCC The austenitization involves crystal structure change,dissolution of cementite,and the diffusion of C. AO TONG UNIVERST K.Chen Taking eutectoidal steel as an example to study the formation mechanism of austenite. Orthorhombic:all three bases intersect at 90 angles,so the three lattice vectors remain mutually orthogonal;a,b,and c are distinct. 11- Taking eutectoidal steel as an example to study the formation mechanism of austenite. - Orthorhombic: all three bases intersect at 90° angles, so the three lattice vectors remain mutually orthogonal; a, b, and c are distinct. 11