見かけの熱伝導率を用いた大型ビレットの鋳造初期シミュレーション

Abstract

The computer simulation program concerned with the continuous casting of 0.5m diameter 6063 aluminum billet was completed using the steady-state difference method proposed by Adenis et al. From the measured isotherm profiles it was concluded that the ingot had not reached the steady-state in the initial 2m. In order to simulate the temperature distributions of these non-steady-state ingots using the same program, experimental formulas were proposed using the apparent thermal conductivity in the solid phase, taking the initial strong cooling effects into consideration. Three experimental results were obtained with casting velocity 0.75m/s: the thermocouple heads were inserted when the billet length was 0.6m (run a), 1.0m (run b) and 1.2m (run c), respectively. Corresponding to these experiments the following K equations were selected. run a: K=175+586×t-1/2run b: K=251-100×10-3trun c: K=230-75.3×10-3tIn run a, the heat transfer coefficient from the high temperature region of the billet surface to the cooling water was also improved to obtain good agreement with experimental data.