关键词: 温度场, 返红, 层流冷却, 冷却速度, 热轧带钢, 有限元

Abstract: Analyzes the temperature field of hot rolled strip during laminar cooling by finite element method, and calculates the cooling rate at typical positions to investigate how the cooling rate variea periodically during water cooling and subsequent re-reddening. It is found that there is a critical line of cooling rate at the position that is sectionally 1/3 half-thickness away from the strip surface, and the cooling rate varies alternately between positive and negative values between the surface and the critical line. It implies that the critical line is in fact a demarcation line between the transient heat output zone and input zone (re-reddening zone) in cooling process. A regression model for the relationship among re-reddening temperature, time and distances from different node points to the surface is thus obtained in re-reddening zone. The results can be used as reference for the prediction and control of microstructures and properties of strips in rolling process.