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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。
Through a single-pass thermal simulation test of niobium microalloyed steel with different strain rates (0.01 ~ 10 s-1) at high temperature (900-1100 ℃) and microstructure observation, the effects of thermal deformation parameters on dynamic recrystallization The dynamic activation energy of dynamic recrystallization and the related parameters were obtained, and the constitutive equation of the steel was established. The experimental results show that the addition of alloying elements increases the dynamic recrystallization activation energy due to the drag of solid solution atoms and the pinning effect of precipitates, and significantly inhibits the dynamic recrystallization and grain growth of the steel. The original austenite grain size increases, the deformation temperature decreases and the strain rate increases will inhibit the dynamic recrystallization process.