Noncontact Modulated Laser Calorimetry for Liquid Austenitic Stainless Steel in dc Magnetic Field

A newly developed noncontact modulated laser calorimetry method was attempted to measure the isobaric specific heat capacity and thermal conductivity of liquid austenitic stainless steel (SUS 304: Japanese Industrial Standards). A stainless steel droplet was electromagnetically levitated in a radio frequency coil. A dc magnetic field of 4–5 T was superimposed to the droplet to suppress the convection in the droplet by the Lorenz force. The specific heat capacity of the liquid SUS 304 was successfully measured at temperatures ranging from 1750 to 1970 K. No clear temperature dependence was observed. The mean value over the whole temperature range is 794±76 J·kg−1·K−1.The lower thermal conductivity of the liquid SUS 304 was obtained at higher dc magnetic field, which indicates that convection in the droplet was reduced by dc magnetic field. The thermal conductivity was measured as 60±9 W·m−1·K−1 at 5 T in the same temperature range. For the thermal conductivity measurement, it is necessary to verify the effect of suppression of the convection by conducting the calorimetry at higher dc magnetic field.