Understanding crystallographic orientation, microstructure and mechanical properties dependent interaction between recrystallization and phase transformation of a Fe–Al–Mn–Mo–C dual-phase steel

Abstract

The competition mechanism of ferritic recrystallization and austenitic transformation, nucleation and growth kinetics of different crystallographic orientation components during intercritical annealing of a cold-rolling Fe–Al–Mn–Mo–C deep drawing dual-phase steel were investigated by a series of continuous annealing simulation experiments. The experiments provided an insight into the microstructural characteristics and mechanical behaviors that were caused from the interaction of primary recrystallization and phase transformation. The results show that the promoting effect of austenite transformation is greater than that of ferrite recrystallization with the increase of temperature in the two-phase region, and an appropriate soaking time is contributed to the formation and development of {111} oriented grains. Austenite formation affects morphology and size of the microstructure owing to inhibiting ferrite recrystallization and growth. From these that experimental data of the observed temperature or time-dependent mechanical properties can be interpreted. An excellent comprehensive properties with tensile strength of 480 MPa and plastic strain ratio (r value) of 1.15 can be obtained at annealing temperature of 880 °C for 300 s.

Keywords

• Deep drawing dual-phase steel
• Intercritical annealing
• Ferrite recrystallization
• Austenite transformation
• Mechanical properties