Formation Mechanism 上游充道大粤 SHANGHAI JIAO TONG UNIVERSITY 2.Austenite Nucleus Growth ⊕ After austenite nucleation,two interphase interfaces formed:y/a and y/Fe C The growth of austenite nucleus is the migration of y/a into a and vWfe3 C into FegC∠目ea Assume all interfaces are planar,carbon concentration in each phase can be determined from the phase diagram of Fe-FeaC AN I JIAO TONG UNIV K.Chen 15K. Chen Formation Mechanism 15 2. Austenite Nucleus Growth After austenite nucleation, two interphase interfaces formed: γ/α and γ/Fe3C The growth of austenite nucleus is the migration of γ/α into α and γ/Fe3C into Fe3C Assume all interfaces are planar, carbon concentration in each phase can be determined from the phase diagram of Fe-Fe3C