Effect of intercritical annealing time on microstructure and deformation mechanism of high bainite dual phase steels

In this study, Ferrite-Bainite dual phase structure steels were produced using appropriate heat treatment and according to intercritical annealing holding time dual phase steels with different ferrite volume fraction (Vf) were produced. Samples of these steels with dual phase structure were tensile tested at room temperature. Results showed that the yield strength and work hardening decrease linearly with increasing Vf whilst ductility decreases. It was ascertained that during deformation of these steels at studied Vf range two stage of work hardening take place. Finally variation of mechanical properties and Hollomon equation parameters with differing Vf have been used to rationalize deformation mechanisms activated at different stages of deformation.

Keywords:

Dual phase steels , ferrite , bainite , intercritical annealing , Deformation