Learn about the lower rack
Rack forging and machining may produce residual stress, if not after the solution of treatment on heat treatment, will be superimposed with quenching distortion, will occur a great distortion, and thus should be taken in advance to greatly reduce the stress at annealing, normalizing, tempering, etc., in order to solve the treatment of residual stress.
Usually annealing, normalizing is often used to improve the cutting performance and appearance roughness of the measure gear, greatly reduce the cutting residual stress situation. Tempering heat treatment is applied to strengthen the heart of the gear strength and toughness, as well as greatly reduce the quenching distortion situation. The preparatory heat treatment of gears is important for the control of gear distortion. Preliminary heat treatment includes annealing, normal normalizing, isothermal normalizing and tempering heat treatment. Preliminary heat treatment process can be arranged before machining, in the middle of machining, etc. as needed.