Thermodynamic Calculation of Microalloyed Precipitation in Austenite Region for Fe-C-N-Al-Ti-V Steel

A thermodynamic model of the microalloyed elements precipitation in austenite region for Fe-C-N-Al-Ti-V steel has been established.The computing results show that vanadium can precipitate from the austenite as long as the amount of nitrogen and vanadium can be increased although the solubility of V (CN) is high.When the nitrogen content in the steel is higher, effect of carbon on vanadium precipitation is slight.Even though increasing the amount of vanadium, nitrogen and carbon, V (CN) precipitates at the lower temperature of austenitic mainly too.Because of the great solubility of V (CN) in the austenite which is different from the Nb (CN), the lower reheating temperature can be adopted before rolling and so the smaller initial grains can be gained.