一种铌微合金钢热变形过程中的动态再结晶
Dynamic Recrystallization Behavior of Nb Micro-alloyed Steel During Hot Deformation
朱利敏, 文九巴
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作者单位：(河南科技大学 材料科学与工程学院 有色金属重点实验室, 河南 洛阳 471003)
中文关键字：动态再结晶； 热变形； 微合金钢； 热模拟
英文关键字：dynamic recrystallization; hot deformation; micro-alloyed steel; thermo-mechanical simulator
中文摘要：通过一种铌微合金钢高温下(900～1100℃)不同应变速率(0.01～10 s-1)的热模拟单道次压缩试验，结合组织观察， 研究了热变形参数对动态再结晶过程的影响，求出动态再结晶形变激活能及相关参数，建立了该钢的热变形本构方程。 实验结果表明，合金元素的添加，由于固溶原子拖曳及析出物的钉扎作用，增加了动态再结晶激活能，显著抑制了该钢的动态再结晶及晶粒长大过程。原始奥氏体晶粒尺寸增大、变形温度降低及应变速率增大将抑制动态再结晶过程。
英文摘要：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.