Dynamic Recrystallization Behavior of Nb Micro-alloyed Steel During Hot Deformation

A micro-alloyed pipeline steel was deformed in compression at high temperature(900 ℃～1100 ℃) and strain rate from 0.01 s-1 to 10 s-1 using Gleeble 2000 thermo-mechanical simulator.By analyzing the curves of the flow stress and the microstructure,the effects of thermo-mechanical treatment parameters on dynamic recrystallization(DRX) behavior of observing the steel were investigated.The results show that the addition of microalloy elements produces a retardation of dynamic recrystallization and grain growing because of increasing active energy of dynamic recrystallization under the action of solid solution drawing and precipitate pinning.The initial austenite grain size,deformation conditions(temperature,strain and strain rate) affect dynamic recrystallization kinetics.