Behavior of Eurofer97 reduced activation martensitic steel upon heating and continuous cooling

The phase transformation behavior of the Eurofer97 steel (Fe9Cr1WVTa) has been investigated. The transformation temperatures upon heating and cooling were determined by dilatometry for different rates in the range 0.0028–100 °C/s. The prior austenitic grain size of Eurofer97, measured as a function of the austenitization temperature, does not change appreciably up to 1050 °C and then increases with increasing austenite temperature from 1050 up to 1200 °C. Continuous cooling transformation diagrams were determined for the austenitization temperatures of 980, 1060 and 1140 °C. They show a well-known form with two main phase fields, martensite and ferrite. Values of the critical cooling rates and ferrite start temperatures depend on the austenitization temperature. After thermal cycles samples were further characterized by optical microscopy, scanning electron microscopy and thermoelectric power measurements.