Microstructure evolution during isochronal annealing of a 42% cold rolled TRIP-TWIP steel

S Pramanik, A A Saleh, D B Santos, E V Pereloma, A A Gazder
2015 IOP Conference Series: Materials Science and Engineering  
A high manganese TRIP-TWIP steel was cold rolled to 42% thickness reduction and isochronally annealed between 600 to 900 °C for 300 s. The microstructural evolution during annealing was studied by high resolution electron back-scattering diffraction. After cold rolling, the steel comprised predominant fraction of α′-martensite, a small fraction of blocky ε-martensite and a trace fraction of retained austenite (γ). During annealing, the reversion of ε and α′ martensite to γ was followed by the
more » ... s followed by the recrystallisation of γ. While the processes of reversion to and recrystallisation of γ were completed by 700 °C, further annealing between 750 to 900 °C led to γ grain growth. A novel method to delineate the γ-γ grain boundaries was developed in order to accurately quantify γ grain size and subsequently the activation energy for γ grain growth. Abstract. A high manganese TRIP-TWIP steel was cold rolled to 42% thickness reduction and isochronally annealed between 600 to 900 °C for 300 s. The microstructural evolution during annealing was studied by high resolution electron back-scattering diffraction. After cold rolling, the steel comprised predominant fraction of α′-martensite, a small fraction of blocky ε-martensite and a trace fraction of retained austenite (γ). During annealing, the reversion of ε and α′ martensite to γ was followed by the recrystallisation of γ. While the processes of reversion to and recrystallisation of γ were completed by 700 °C, further annealing between 750 to 900 °C led to γ grain growth. A novel method to delineate the γ-γ grain boundaries was developed in order to accurately quantify γ grain size and subsequently the activation energy for γ grain growth.
doi:10.1088/1757-899x/89/1/012042 fatcat:v2uivu4jmbf3lhof2pdwopc3na