Microstructure and Properties of Vanadium-bearing DP980 Steels Processed with Continuous Galvanizing Line Simulations

A study is being conducted of additions of the microalloying elements Nb,V and V-N to a low carbon,high-strength （980 grade） Dual-Phase steel that was processed using a CGL simulation. In this study,compositions with a common base but containing various additions of V or Nb with or without high N were designed and subjected to Gleeble simulations of different galvanizing （GI）,galvannealing （GA） and super cooling processing. These experiments were supplemented with additional heat treatments performed using a quartz filament furnace. The results revealed that the phase balance （martensite-bainite-ferrite）was strongly influenced by the different microalloying additions,while the strengths of each phase were somewhat less affected. UTS levels of 1 100 MPa,along with good levels of ductility and work hardening,were measured in steels containing less than 0.1% C and 1.75% Mn. The results of this program will be presented and discussed.