Numerical modelling of the heat transfer in and around a steel bar during hot rolling

Abstract

By modelling the heat transfer in and around a hot-rolled steel bar, the temperature distribution in the bar can be predicted at any stage of the hot rolling process. Knowledge of these temperatures is useful when the process is to be optimized. This paper presents a finite difference simulation of the heat transfer and resulting temperature distribution. The numerical procedure accounts for thermal radiation from the bar, convective heat transfer to the atmosphere and cooling water, and conduction between the moving bar and the mill rolls and manipulators. Measured values for convective heat transfer coefficients are used at the boundaries. The following effects are also accounted for in the procedure: deformation of the bar during rolling, tilting the bar between passes through a mill, cropping the bar and contraction resulting from heat losses. Predicted and measured temperatures correlate favourably.

An integrated thermal model of hot rolling

“…Natural convection prevails at low speeds, but forced convection dominates when the plates move faster, see [4]. The heat transfer coefficients for forced convection depend on the current velocity of the plate, e.g., [5,[14][15][16], and can be calculated by the formulae given in [17] or [18]. In the current paper, only forced convection is taken into account incorporating the plate velocity.…”