Author/Authors :
Ghatei Kalashami، A. نويسنده Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran , , Kermanpur، A. نويسنده , , Najafizadeh، A. نويسنده , , Mazaheri، Y. نويسنده Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran ,
Abstract :
An ultrafine grained dual phase (UFG DP) steel containing niobium was produced by a new route
utilizing simple cold-rolling and subsequent intercritical annealing of ferrite/martensite duplex starting
structures. The effects of intercritical holding time on the microstructural evolutions and mechanical
properties were studied. The results showed that increasing intercritical holding time enhnaced the
volume fraction of martensite and decreased the grain size of ferrite. Tensile testing also revealed
good strength–elongation balance for UFG DP steels (UTS×UE > 100 Jcm-3), in comparison with the
commercially used high strength steels. The variations of strength, elongation and fracture behavior with
intercritical holding time were correlated with the microstructural features.
