The Effect of Prior Austenite Grain Size on Microstructure of Medium Carbon Dual Phase Steels
Ersoy Erişir Özge Ararat Oğuz Gürkan Bilir
AbstractFiner martensitic and ferritic microstructures are demanded to obtain high strength and toughness for dual phase steels. In this study, reducing of prior austenite grain size selected as an effective method to reduce the size of dual phase microstructure. The effect of prior austenite grain size on microstructure of medium carbon dual phase steel produced by intercritical annealing were investigated for different austenitizing conditions. Annealing experiments were performed to fully austenitizate the steel at different austenitizing temperatures (900, 950, 1000ᵒC) and times (5, 10, 15 min) and followed by quenching. Finally, as-quenched martensitic microstructures were intercritical annealed at 760ᵒC for 15 min to attain martensitic and ferritic dual phase steel. The microstructures were analyzed using light microscopy and image analysis methods. It is concluded that grain size of dual phase steel is reducing by decreasing of the austenitizing temperature and the holding time.