Acylindrical steel ingot 150 mm in diameter and 400 mm long passes through a heat treatment furnace which is 6 m in length. the ingot must reach a temperature of 850 °c before it comes out of the furnace. the furnace gas is at 1280 °c and ingot initial temperature is 100 °c. what is the maximum speed with which the ingot should move in the furnace to attain the required temperature? the combined radiative and convective surface heat transfer coefficient is 100 w/m2 °c. take kisteel 45 w/m°c and a (thermal diffusivity) 0.46x10-5 m2/s ans. 1.619x10-m/s