Steel balls 12 mm in diameter are annealed by heating to
Diameter of steel balls = 12 mm. Annealed by heating to temperature = 1150 K. Temperature when cooling process is done slowly = 400 K. Temperature of air environment t 4 = 325 K. Convective heat transfer coefficient h = 20 W/m 2. K. Properties of steel: Thermal conductivity (K) = 40 W/m . K. Density = 7800 Kg/m 3. Specific heat (c) = 600 J/Kg . K