PREDICTION OF FERRITE GRAIN-SIZE AFTER WARM DEFORMATION OF LOW-CARBONSTEEL

When deformation is carried out near the A(1) temperature in low carbo n steel, ferrite recrystallisation appears to be the dominant mechanis m in controlling the grain size. The present investigation has shown t he dominance of ferrite recrystallisation at low temperatures between 665-690 degrees C by the application of an austenite recrystallisation power law on experimentally measured grain sizes in 0.05% C steel. Co mparison has also been made between predictions using this power law a nd the experimentally measured grain size after deformation in the two phase (alpha + gamma) region. The results show that the ferrite grain size is influenced significantly by the relative proportions of gamma and alpha phases within the structure just prior to deformation. In a ddition the good correlation found between predicted and measured grai n sites indicates that ferrite recrystallisation dominates between 850 -690 degrees C. Despite this, the possibility still exists for the occ urrence of a transformation induced mechanism within this temperature region.