Arrangement sequence of heat treatment process

According to the different purposes of heat treatment and process functions, the process location should be reasonably arranged.

1. Annealing and normalizing

Annealing and normalizing are usually used as preparatory heat treatment processes. Generally, they are arranged after the production of blank and before the machining. For the precision workpiece, in order to eliminate the residual stress of the machining, the stress relief annealing should be arranged between the machining. The process route is arranged as follows:

Rough production (casting, forging, welding, stamping, etc.) - annealing or normalizing - machining.

2. Tempering treatment

Quenching and tempering can be used not only as heat treatment, but also as surface quenching in the future and preparing for the quenching of the precision workpiece which is easy to deform. The quenching and tempering process is generally arranged after the rough machining and before the finishing or semi finishing. The process is arranged as follows:

Blanking forging normalizing (annealing). Rough machining (allowance). Conditioning. Finishing.

3. Quenching and tempering

In production, the position of quenching and tempering shall be considered according to whether the hardness after tempering is convenient for processing. Generally, there are two situations. One is that after tempering, the hardness is high and the cutting is difficult. Then the quenching and tempering are placed after cutting and before grinding. The process route is as follows:

Blanking. Forging. Normalizing (annealing). Rough machining. Quenching and tempering (HRC < 35) - grinding.

Another situation is: after tempering, the hardness is required to be low and the cutting is not difficult, so the quenching and tempering are put before the finishing, and the process arrangement is as follows:

Blanking forging normalizing (annealing) roughing. Quenching and tempering. Finishing grinding.