Determination of Secondary Cooling Zone Heat Transfer Coefficient with Different Alloy Types and Roughness in DC Casting by Inverse Heat Conduction Method

The cooling characteristic curves in a heated ingot with diameter of 100 mm quenched by water jet were measured under different conditions. A two-dimensional calculation model was established to calculate the HTC magnesium alloy spray cooling. Data from cast-in thermocouples trail input into and HTCs back-calculated for quench region. calculated types roughness conditions, relationship between surface temperature, roughness, accordingly. results show that greater thermal conductivity alloy, heat transfer coefficient (HTC). AZ80, AZ31, ZK60 alloys increase successively. With decrease both impingement zone free−falling shows trend rapid at first, then slowly increasing maximum value, finally, decrease, peak value appearing about 400 K. Considering influence temperature on HTC, mathematical relationships them are established.