Arrangement sequence of heat treatment process

Arrangement sequence of heat treatment process

According to the different purpose of heat treatment and process function, the process location shall be reasonably arranged.

1. Annealing and normalizing

Annealing and normalizing are usually used as preparatory heat treatment processes, which are generally arranged after blank production and before cutting. For precision workpieces, stress relief annealing shall also be arranged between cutting and machining in order to eliminate the residual stress of cutting. The process route is arranged as follows:

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

2. Quenching and tempering treatment

Quenching and tempering treatment can be used not only as heat treatment, but also as surface quenching and preparation for quenching of precision workpieces that are easy to deform. The quenching and tempering process is generally arranged after rough machining and before finishing or semi finishing machining. The process arrangement is as follows:

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

3. Quenching and tempering

During production, the quenching and tempering positions shall be considered according to whether the tempered hardness is convenient for processing. Generally, there are two situations. One is that the hardness is high and cutting is difficult after tempering, so 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 that after tempering, the hardness is required to be low and cutting is not difficult, so quenching and tempering shall be placed before finishing, and the process arrangement is as follows:

Blanking forging normalizing annealing rough machining. Quenching and tempering. Finish machining and grinding.