Effects of deformation of austenite on bainite transformation in niobium microalloyed low carbon steel

Bainite transformation in niobium microalloyed steel during the continuous cooling conditions has been researched by using Gleeble-1500 thermomechanical simulator.The results showed that with the increasing of temperature the amount of proeutectoid ferrite decreased,and the bainite lath became large.The amount of bainte decreased with the increasing of the strain rate,but the influence of strain rate on the amount of bainite transformation diminished with the increasing of the cooling rate.The stability of austenite increased with the increasing of the holding time after deformation,and the retained austenite existed at the end of transformation under higher cooling rate.