Heat Treatment Systems for Forged Wheels
Wheel rim forgings are moved through the solution annealing furnace in two rows. They are carried by a four-strand chain conveyor. In the event of a malfunction the conveyor can oscillate. The conveyor chain passes through the entire nozzle field of the solution annealing furnace and returns to the loading point inside the furnace chamber.
The unloading position is exactly above the axis of the chain return wheels. Light barriers are provided for part presence checking. The furnace door openings at the entry and exit ends allow two wheels to be loaded and unloaded side-by-side at a time.
The furnaces are heated either electrically or with natural gas, depending on the customer's choice. The wheels travel horizontally through the furnace in two single-level rows and are heated by the high convection impingement flow principle. To this end, close-pitched hot-gas nozzles are uniformly arranged above the conveyor plane, delivering gas at a very high velocity. The nozzle array is designed to suit the shape of the parts being heated so as to ensure a uniform, rapid heat transfer.
The heated furnace length is divided into mutually independent control zones. Each control zone is fitted with one (solution annealing furnaces) or two (artificial ageing furnaces) circulating fans in the furnace roof. All components inside the furnace chamber of the solution annealing furnace, as well as the panels covering the furnace insulation, are made of high-alloyed, heat resistant CrNi steel. The same holds true for the chain conveyor, its deflection wheels, and the guide and support system.