通过显微组织观察实验,对细晶高强IF钢在不同加热温度和保温时间下奥氏体晶粒长大规律进行研究。结果表明:随加热温度升高、保温时间延长,奥氏体晶粒尺寸逐渐增大。由实验结果可知细晶高强IF钢的晶粒粗化温度为1050℃,晶粒粗化时间为40 min。为保证微合金元素充分固溶,同时获得细小的奥氏体晶粒,生产中将加热温度控制在1050~1100℃、保温时间控制在30 min~40 min。通过对实验数据进行非线性回归建立了细晶高强IF钢奥氏体晶粒长大规律的数学模型,模型的计算结果与实验结果基本吻合。 Through the microstructure observation experiment, the regularity of austenite grain growth under different heating temperature and holding time was studied. The results show that the austenite grain size increases with the increase of heating temperature and holding time. The experimental results show that the grain coarsening temperature of fine-grain high-strength IF steel is 1050 ℃, and the coarsening time of grain is 40 min. In order to ensure the micro-alloying elemental solid solution, and get the austenite grain, the heating temperature is controlled at 1050 ~ 1100 ℃ and the holding time at 30 min ~ 40 min. The mathematical model of austenite grain growth was established by nonlinear regression of the experimental data. The calculated results of the model are in good agreement with the experimental results.