Fibre Insulation Refractories in Reheating Furnaces

Abstract

Reheating furnaces are the heart of a rolling and forging shop. Primary steel Ingot In changing shapes Into blooms, billets, bars, rods, slabs, plates, sheets, strips, rails, angles, channels and tubes has to be heated into pyro-plastic stage at 1200-1320°C in a reheating furnace. The temperature Is dependent upon the steel composition and rolling/forging technique. Hardy and Titteringtonl has dealt with the refractories of reheating furnaces. At this temperature enough iron oxide scale formation takes place due to which the hearth of the furnace has to bear the corrosive action of molten iron oxide and the walls, oxide atmosphere. In the heat treatment furnaces for annealing, normalising, hardening or stress relieving, the temperature Is never more than 1020°C and Is generally around 780°C. But unlike reheating furnaces the atmosphere Is either reducing or neutral without any suspension of inorganic material. Except for its hearth which has to bear the load of the work pieces, all the walls and roof has to withstand and conserve the heat only.