高碳钢奥氏体晶粒长大的预测

Prediction on Austenite Grain Growth in High Carbon Steel

借助于高温共聚焦显微镜(CLSM)、透射电镜(TEM)研究含Ti钢和无Ti钢的奥氏体晶粒长大行为。试样在1123~1473K之间保温60min时测量一系列温度下不同保温时间的奥氏体晶粒尺寸。结果表明:两种钢奥氏体晶粒尺寸随着温度的上升而增大;另外,两种钢奥氏体晶粒尺寸随时间的延长而长大,并符合抛物线方程。并且,观察到了第二相粒子,用第二相粒子的熟化公式和体积公式分别计算两种钢的含Ti粒子尺寸与体积分数。同时,采用修正的Gladman公式预测两种钢的奥氏体晶粒长大,实验结果和预测结果吻合较好。

The austenite grain growth behavior of Ti-bearing and Ti-free steel was investigated using confocal laser scanning microscope （CLSM） and transmission electron microscope （T EM ）. Samples were held for 60min at 1123-1473K and then austenite grain sizes for different holding time at a series of temperatures were measured. The results show that austenite grain size of both steels increases with the increase of temperature. Besides, the austenite grain size of both steels grows with the hold-ing time, which meets parabolic equation. The second phase particle was observed. The equation of Ostwald ripening was introduced to calculate the size of particle, and the volume fraction equation of second phase particle was applied to calculate the volume fraction of particle. Meanwhile, the modified Gladman model was adopted to predict austenite grain growth. The predicted results agree well with the measured results.