Influence of the Chemical Composition on Transformation Behavior of Low Carbon Microalloyed Steels under Continuous Cooling

摘要

In order to design thermomechanical treatments for processing low carbon microalloyed steels, the various critical transformation temperatures, i.e. the start and finish of the austenite transformation (A{sub}(r1), A{sub}(r3)) and the no-recrystallization temperature (T{sub}(nr)), must be determined. Continuous cooling torsion and compression testing is a useful way to measure these values. In this study six low carbon microalloyed steels with different additions (Nb, Cu, Si, Mo) were examined using these techniques. Results show that Nb has no effect on transformation temperatures but the T{sub}(nr) increases as Nb contents are increased. On the other hand, the addition of Cu retards the austenite to ferrite transformation and Si seems to retard recrystallization by reducing Nb solute drag effect.