Affect the aluminum quenching and holding time factors:
(1) Heating temperature. The higher the temperature, the greater the phase transition speed, the shorter the holding time. If the 2A12 alloy at 500 ℃ for 10min, the strengthening phase can be dissolved, after natural aging to obtain the strength of up to 450MPa; if the heating temperature of 480 ℃, need to heat 15min, and the natural aging strength of 420MPa, 500 ℃ quenching, aging 30MPa after low.
(2) Industrial aluminum pre-treatment and the original state of the organization (including strengthening the size and distribution). The second cast alloy usually relatively coarse, the dissolution process is very slow, the required insulation time is much longer than the deformation of aluminum profiles. As for the same deformation alloy, the deformation time is short and the time required for the deformation is short. In the annealed aluminum profile, the size of the strengthened phase is larger than the alloy after quenching and aging, and the former requires much longer holding time than the later quenching.
(3) industrial aluminum size. In the same heating conditions and the same amount of loading conditions, the large size of industrial aluminum profile smaller than the size of the insulation time is much longer. Small size aluminum heating to the quenching temperature, holding a few minutes or a few minutes to make the temperature inside and outside reach the same balance; and large-size industrial aluminum, the surface temperature reaches the quenching temperature, the center temperature is still far lower In quenching the required temperature, so profiles have a temperature gradient, the temperature gradient disappears, the internal and external temperature to balance. Obviously, the larger industrial aluminum products, heat transfer to balance the longer, the correspondingly extended holding time. Thickness or diameter of less than 3mm profile only heat 30min, but the wall thickness or diameter greater than 100mm profile is required insulation 210min.