Aluminum alloy die forgings are widely used in parts with medium and high strength because of their small specific gravity, good thermal conductivity, high conductivity and corrosion resistance. In practice, the quality control of folding and cracking of aluminium alloy die forgings should focus on prevention, combine process technology with production management, and achieve the following specific aspects:
(1) The technical status of forging equipment, process equipment and blanks should be analyzed to make the forging process conform to the actual production and be advanced, reasonable, complete and accurate.
(2) In the design of forging die, the forming force and the tonnage of equipment needed for forging should be considered, the volume of billet or intermediate billet should be reasonably allocated, the correct filling method should be selected, the filling radius or the inclination of forging at the transition point of the forging die chamber should be increased, and the surface roughness of the die chamber (including the flying edge bridge) should be reduced.
(3) Aluminum alloy raw materials used should be guaranteed free of defects such as folding, cracking and coarse-grained rings. For billet heating, the charging quantity should be strictly controlled, and the billet should be turned over within half of the heating time, so as to reduce the time from discharging to forging as much as possible.
(4) In forging operation, the deformation degree or hammering force of blank should be correctly controlled according to the operation principle of priority and priority, the anisotropy of extrusion raw materials should be reasonably utilized, the forging die and operating tools should be correctly preheated, and the forging die (especially the upper die chamber) should be lubricated reasonably.
(5) In forging production, the head of the production team should be under the unified command, the first piece inspection should be coordinated by the competent technical personnel, and the production should be guided by the shift operation if necessary. At the same time, the first batch of first pieces should be arranged in the day shift production as far as possible to facilitate the discovery of quality defects of forgings. After confirming that there are no defects such as folds and cracks, the production can be evenly and rhythmically balanced within the prescribed time interval. 。
(6) In forging inspection, the first piece inspection should be done, the "three inspection system" should be strictly implemented, and the process inspection, intermediate inspection, itinerant inspection and final inspection should be done to prevent the systematic quality defects from flowing into the next process.