Specific features of design and operation of ″Holkroft″ automatic lines for chemical heat treatment

Automatic line for chemical heat treatment of gears which is in operation at the Volga's automobile plant is described. The line includes a carbonitriding furnace, a hardening tank, a washing machine, a temper furnace and a charging conveyor. The furnace is equipped with U-shaped radiant tubes arranged horizontally under crown. Natural gas, ammonia and endogas are supplied from two sides of the furnace into the work space. Carbonitrided gears are subjected to oil quenching, washing and tempering. The design of endothermic generator excludes environmental effects on gas quality. The advantages of ″Holkroft″ carbonitriding lines are shown.