an industrial furnace for heating metal ingots and stock before pressure working (rolling, forging, or stamping). According to the method of operation, a distinction is made between batch furnaces (soaking pits and compartment furnaces) and continuous furnaces (holding, rotary-ring, rotary, and car-bottom furnaces).
Soaking pits are used in ferrous metallurgy to heat ingots preparatory to rolling in blooming and slabbing mills. Stock for section and sheet rolling is heated in holding furnaces (particularly in walking-beam furnaces). Round stock for rolling tubes and wheels is heated in rotary-ring furnaces. Modern rolling mills in nonferrous metallurgy plants are equipped with continuous pusher-type furnaces, rotary-ring and car-bottom furnaces, and walking-beam furnaces. The highly versatile compartment furnaces with bogie-type or fixed hearths are used in the machine-building industry in forging and repair shops during individual and small-series production. Holding pusher-type furnaces are used in mass production, whereas rotary-ring and rotary furnaces are being increasingly widely used in shops for hot pressure working in automotive and tractor plants. In ferrous metallurgy, heating furnaces are usually fired with blastfurnace, coke-oven blast-furnace, or natural blast-furnace gas; in other branches of industry, furnaces are fired with fuel oil or natural gas, which is the most promising fuel on a long-term basis.
V. M. TYMCHAK