Homogenizing annealing thermal treatment technology for A390 aluminum alloy cast ingot

The invention belongs to the technical field of metal material thermal treatment, and particularly relates to a homogenizing annealing thermal treatment technology for an A390 aluminum alloy cast ingot. The homogenizing annealing thermal treatment technology comprises the steps that the A390 cast ingot obtained through the electromagnetic stirring-semicontinuous casting technology is placed in a heating furnace to be heated to 350-500 DEG C, the temperature is maintained for 2-6 h, and then, the cast ingot is cooled to 250 DEG C in the furnace and finally discharged to be subjected to air cooling. According to the homogenizing annealing thermal treatment technology, the Brinell hardness of the A390 aluminum alloy cast ingot is reduced to be below 70 HB from 130 HB, and ductility is increased to be more than 8% from 2.5%. The homogenizing annealing thermal treatment technology is conducted on the A390 aluminum alloy cast ingot. Due to dissolution of an alloy phase and elimination of microsegregation, the composite structure homogeneity of the A390 aluminum alloy cast ingot is improved, the microstructure of alloy is improved, the residual stress is eliminated, and the machinability of the alloy is improved. The technology is simple, cost is low, the high production efficiency is achieved, and the homogenizing annealing thermal treatment technology is suitable for large-scale industrial production.