Kinetics of Austenite Formation in Dual Phase Steels

Abstract

In this research study a low carbon steel with composition of C=0.11%; Mn=1.30%; Cr=0.45%; Si=0.20%; Al=0.03% and Fe=bal. was cast and used in hot rolled condition. After intercritical annealing at different temperatures for different times, dual phase structures with various volume fraction of martensite were produced. Then the volume fraction of martensite for different samples were measured.
Study of the relationship between temperature and time of intercritical annealing and martensite volume fraction showed that a new equation as f_γ/f_e = 1−exp(−ktⁿ) can be used to give variation of martensite volume fraction with temperature and time of annealing. Also it is found that k coefficient changes exponentially with annealing temperature.