Calculation of Heat Transfer Coefficient at Roll-Solidified Shell Interface of Twin-Roll Type Caster

Abstract

Strip casting experiments on type 304 stainless steel have been carried out in a steel twin-roll caster with rolls 300 mm in diameter and 80 mm wide. The casting speed was 6.68.0 m/min. Thickness of the strips was about 2.4 mm.
Roll temperature was measured at 1mm deep from outer surface of the roll during casting. Abnormal acceleration behavior of temperature change was detected. The annomalous acceleration of the thermo-electromotive force is caused by reduction in solidified shell thickness during squeezing. Calculation by finite difference method agreed with the result of temperature measurements. Simulation revealed that the heat transfer coefficients are, respectively, 2.54.2 and 1016.7 kW/m²K before and after squeezing.