IRREVERSIBLE PHASE-TRANSITIONS IN STEEL

We present a mathematical model for the austenite-pearlite and austeni te-martensite phase transitions in eutectoid carbon steel. The austeni te-pearlite phase change is described by the Additivity Rule. For the austenite-martensite phase change we propose a new rate law, which tak es into account its irreversibility. We investigate questions of exist ence and uniqueness for the three-dimensional model and finally presen t numerical calculations of a continuous cooling transformation diagra m for the eutectoid carbon steel C1080.