During heat treatment, cylindrical pieces of 25 mm diameter, 30 mm height and at 30 degree Celsius are placed in a furnace at 750 degree Celsius with convective coefficient 80 W/m2 degree. Calculate the time required to heat the pieces to 600 degree Celsius. Assume the following property valuesDensity = 7850 kg /m3Specific heat = 480 J/kg KConductivity = 40 W/m degree

• A. 226 sec
• B. 326 sec
• C. 426 sec
• D. 526 sec