Deformation at Elevated Temperature and Transformation during Continuous Cooling of Medium Carbon Steels

摘要

Deformation behavior of two medium carbon steels, S45C and S55C was characterized at their hot-working temperature ranging from 1,423 to 1,523K using high speed compression machine. The effect of strain rate and dynamic softening processes on the flow stresses are reported in the strain rate range between 10-3 and 10s-1. Phase transformation during continuous cooling of these steels was evaluated using dilatometry at various cooling rates between 0.04 to 270 Ks-1. Constitutive equations for plastic deformation and two CCT diagrams were constructed from the experiment data and used in numerical simulation of hot forging processes and prediction of microstructure/hardness of forgings after control cooling.