Classification of heat treatment process

According to different purposes of heat treatment, heat treatment processes can be divided into two categories: preliminary heat treatment and final heat treatment.

1. Preliminary heat treatment

The purpose of preliminary heat treatment is to improve machinability, eliminate internal stress and prepare good metallographic structure for final heat treatment. Its heat treatment processes include annealing, normalizing, aging, quenching and tempering, etc.

(1) Annealing and normalizing
(2) Aging treatment
(3) Conditioning

2. Final heat treatment
The purpose of final heat treatment is to improve mechanical properties such as hardness, wear resistance and strength.

(1) Quenching
(2) Carburizing quenching
(3) Nitriding treatment