A novel type of heat treatment to control austenite stability by precipitation and dissolution of carbide was applied to a 18%Ni-0.6%C steel. The new method enables to study the inherent characteristics of austenite formed by martensitic reversion. The material selected for this study is a hypereutectoid steel with a large carbon solubility gap depending on the austenitizing temperature. The precipitated carbide immediately dissolves into the austenite matrix again after martensitic reversion in order to restore the Ms and Mf temperatures to their initial values. The crystallographic orientation of each phase was mapped by means of the electron back scattering diffraction (EBSD) method using a field emission scanning electron microscope. A full fcc-bcc-fcc reversible martensitic transformations cycle was observed. As a result of the specific heat treatment, the austenite that was formed by martensitic reversion remains stable at ambient temperature.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry