An austenite grain growth model was established by analyzing the quantificational relationship between precipitates and austenite grain size. The austenite grain size of Ti microalloyed steel with the interaction of TiN and TiC particles was calculated by using the austenite grain growth model. The calculated results of the precipitation particle theory indicate that the volume fraction of precipitates gradually decreases and the particle radius increases with increasing temperature. The austenite grain growth is strongly impeded by TiC particles, while the pinning force of TiN on austenite grains is weak. The austenite grain size of the tested steels was measured by a test method at different heating temperatures within 30 min. The results are in good agreement with theoretical calcula-tions.%通过析出粒子与奥氏体晶粒尺寸的定量关系,建立奥氏体晶粒长大模型,计算TiN和TiC析出粒子共同作用下钛微合金化钢奥氏体晶粒尺寸. 根据析出相质点理论计算结果表明:随着加热温度的升高,析出粒子体积分数逐渐减少,粒子半径逐渐增大,TiC粒子强烈阻止奥氏体晶粒长大,TiN粒子对奥氏体晶粒长大钉扎效果一般. 采用实验测试手段测量不同加热温度下保温30 min后实验钢的奥氏体晶粒尺寸,与理论计算结果吻合较好.
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