Five steps of aluminum plate production
Aluminum plates are widely used in aviation, aerospace, construction, printing, transportation, electronics, chemical industry, food, medicine and other industries.
The demand for exterior wall construction and interior decoration, aluminum foil manufacturing, printing, PS plate, manufacturing, household appliances, food packaging and other industries has further increased, becoming the main driving force for the growth of aluminum plate consumption. At the same time, the transportation industry is becoming a new consumption growth point.
Aluminum ingots are directly cast into products after melting at high temperature. Generally, it is melted in an electric arc furnace, then poured into a high temperature resistant mold, and then cooled, crystallized, annealed or cut into products. In production, the melting atmosphere, melting temperature and cooling conditions are mainly controlled to ensure high production efficiency, crystallization meet the requirements and form a network structure.
2. Hot rolling
Hot rolling is relative to cold rolling. Cold rolling is rolling below the recrystallization temperature, while hot rolling is rolling above the recrystallization temperature.
Hot rolling generally refers to rolling above the recrystallization temperature of metal. During hot rolling, there are hardening and softening processes of metal at the same time. Due to the influence of deformation speed, as long as the recovery and recrystallization process is not carried out, there will be certain work hardening. Hot rolling can improve the processing properties of metals and alloys and reduce or eliminate casting defects.
3. Casting and rolling
Cast rolling, also known as ingot free rolling, is a combined forming method of casting method and rolling method.
Casting rolling is a new process that directly "casts and rolls" molten metal into semi-finished billets or finished products. The remarkable feature of this process is that its crystallizer is two rotating cast rolls with water-cooling system, and the melt completes solidification and hot rolling between the roll gaps, and it is completed in a very short time (2 ~ 3S).
Roll casting is a new technology developed in the 1970s. Its advantage is that molten metal liquid directly produces metal products through crystallization, casting and rolling in a rotating crystallizer.
Casting and rolling process flow: liquid metal, front box (liquid level control), casting and rolling mill (lubrication system, cooling water), shear, coiler.
The casting and rolling temperature is generally between 680 ℃ -700 ℃, the lower the better. Generally, the stable casting and rolling line will not stop for more than a month, and the plate will be erected again. During the production process, the liquid level in the front tank needs to be strictly controlled to prevent low liquid level.
4. Cold rolling
Cold rolling refers to the rolling production mode below the recrystallization temperature. Dynamic recrystallization will not occur during rolling, and the temperature will rise to the recovery temperature at most. Cold rolling will appear work hardening state, and the work hardening rate is large. Cold rolled sheet and strip have high dimensional accuracy, good surface quality, uniform microstructure and properties. Products in various states can be obtained with heat treatment. Cold rolling can produce thin strip, and has the disadvantages of large deformation energy consumption and many processing passes.
Finishing equipment can correct the defects produced in the production process of hot rolling and cold rolling, such as edge cracking, oil entrainment, poor flatness, residual stress, etc. it needs to ensure that no other defects are brought into the production process. There are various finishing equipment, mainly including cross cutting, longitudinal shear, tension bending correction, annealing furnace, Slitter, etc.