Interphase Precipitation in Iron Alloys

During the decomposition of austenite to ferrite in certain iron-base alloys a new form of precipitation has been observed at the ferrite/austenite interface. In appropriate alloys, V₄C₃, Mo₂C, and Cr₇C₃ form very fine particles on the interface, which repeatedly moves on to provide fresh sites for further nucleation. The transformation leads to a very fine banded dispersion of carbide in ferrite having striking morphological differences from the same carbides in tempered martensite.