Dissolution of spheroidal cementite in austenite at 910 °C has been studied by means of scanning and transmission electron microscopy. Three different morphologies of transformation have been observed. Most of the particles undergo a more or less homogeneous shrinkage. However, some of the particles transform to austenite by a Widmanstätten type of reaction, whereby austenitic plates form inside the cementite. It is also observed that some of the cementite transforms to M7C3 carbide and austenite by a eutectoid reaction. The results can be understood by considering the phase diagram and assuming that local equilibrium prevails at the phase interface during the reaction.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys