Aluminum sheets and plates are heated to the appropriate temperature, according to the material and the size of the aluminum sheet using different holding time, and then slow cooling (the slowest cooling rate), the purpose is to make the internal organization of the metal to reach or close to the equilibrium state, to obtain good process properties and performance, or for further quenching for tissue preparation.
Aluminum sheets and plates are heated to a suitable temperature and then cooled in air, the effect of normalizing is similar to that of annealing, but the organization obtained is finer, often used to improve the cutting properties of the material, but also sometimes used for some parts with low requirements as the final heat treatment.
After aluminum sheets and plates are heated and insulated, it is rapidly cooled in water, oil or other inorganic salts, organic aqueous solutions and other quenching media. After quenching, the steel part becomes hard, but at the same time becomes brittle. In order to reduce the brittleness of the steel parts, the quenched steel parts in a certain appropriate temperature above room temperature and below 710 ℃ for a long period of holding, and then cooled, this process is called tempering. Annealing, normalizing, quenching, tempering is the overall heat treatment of the "four fires", which is closely related to the quenching and tempering, often used in conjunction with the use of one can not be without;.