Interactions between Recrystallisation and Phase Transformations during Annealing of Cold Rolled Nb-Added TRIP-Aided Steels

V. Andrade-Carozzo; Pascal J. Jacques

doi:10.4028/www.scientific.net/MSF.539-543.4649

Paper Titles

Transformation Behavior of Supercooled Austenite during Hot Deformation of Plain Medium Carbon Steel within (γ+α) 2-Phase Field at a Low Strain Rate
p.4626

Effect of Annealing Time on Microstructural Evolution and Corresponding Mechanical Properties of Cold Drawn Pearlitic Steel Wires
p.4632

Austenite Formation in C35 and C45 Alloys
p.4637

Cold Workability and Magnetic Properties of 6% Si Steel
p.4643

Interactions between Recrystallisation and Phase Transformations during Annealing of Cold Rolled Nb-Added TRIP-Aided Steels
p.4649

Influence of Magnetic Field on the Mechanical Properties of Austempered Ductile Iron (ADI)
p.4657

Gas Quenching with Controllable Heat Extraction
p.4663

Morphological Evolutions in Steels during Continuous Rapid Heating
p.4669

Weldability of Ultra-Fine Grained Atmospheric Corrosion Resistant Steel
p.4675

HomeMaterials Science ForumMaterials Science Forum Vols. 539-543Interactions between Recrystallisation and Phase...

Interactions between Recrystallisation and Phase Transformations during Annealing of Cold Rolled Nb-Added TRIP-Aided Steels

Abstract:

Fe and Fe-C based alloys present the exceptional feature that the processing route can be adapted to lead to various phases that present antagonist mechanical properties ranging from soft ferrite to high strength martensite. Among the different deformation mechanisms that can be exhibited by these phases, the TRIP effect brings about large enhancements of the work-hardening rate. The current TRIP-assisted multiphase steels present a ferrite-based matrix with a distribution of islands of bainite and retained austenite obtained at the end of specific thermal or thermomechanical treatments. The present study aims at characterising the interactions occurring between ferrite recrystallisation and austenite formation during the intercritical annealing of cold rolled Nb-added TRIP-aided steels. It is shown that the addition of niobium retards the ferrite recrystallisation during heating. As a consequence, ferrite may not be completely recrystallised before the nucleation and growth of the austenite grains. Strong interactions between these phenomena can then be observed, i.e. a strong hindering of the ferrite recrystallisation due to the austenite formation. Furthermore, the heating rate from room temperature to the intercritical temperature range influences the thermodynamic conditions prevailing at the ferrite / austenite interface and dictates the phase proportions.