3004 aluminum alloy is used for punching cans, ship decks, food and beverage packaging and other industries. 3004 aluminum alloy punched cans have a high yield rate, good decorative properties, strong plasticity and excellent corrosion resistance. Currently, the 3004 aluminum alloy manufacturing process uses the direct water cooling method (DC method), including casting, ingot homogenization heat treatment, hot rolling, recrystallization annealing, cold rolling, and annealing. Due to the large amount of deformation of the 3004 aluminum alloy, and the high surface quality requirements of the 3004 aluminum alloy strip. Although the above method is successful, the Aluminum Strip Continuous Casting and Rolling processing cost is relatively high. For this reason, it is considered to process 3004 aluminum alloy by casting and rolling method, which refers to a process method of directly “making and rolling” a metal melt into a semi-finished blank or finished product. The distinguishing feature of this process is that its crystallizer is two rotating rolls with water cooling system. The melt completes the two processes of solidification and hot rolling between its roll gaps, and it is completed in a short time (2s~3s).
Aluminum Strip Continuous Casting and Rolling
The basic process of aluminum strip continuous casting and rolling process is: aluminum ingot → melting furnace → static furnace → degassing unit→ filtering unit → casting nozzle → rolling mill → intermediate unit → coiling machine.
It is characterized by casting and rolling molten aluminum into 6-10mm thick, 650-1400mm wide slab and rewinding, and then directly sent to the cold rolling mill for finishing rolling. So that in the production process of aluminum sheet and strip, the ingot is omitted, heating, hot rolling, billet opening, etc., not only shorten the process flow of aluminum sheet and strip production, greatly reduce the construction capital of the project, but also reduce the metal burning loss during the production process, save energy, and at the same time can easily achieve aluminum sheet continuous production of strip.
Continuous Casting and Rolling Method
1. Put the charge into the smelting furnace, smelt into a melt at 700 °C ~ 800 °C, argon refining once every 1.5h ~ 2.5h, slag once;
2. Introduce the melt into the stationary furnace, keep the temperature in the stationary furnace at 725℃～740℃, add the refining agent 2kg/t～3kg/t after standing for 15min～1h, and remove the slag once after refining.
3. Introduce the melt in the static furnace into the degassing box, and pass the argon gas degassing and refining every 1.5h~2.5h, and strip the slag every 1h.
4. Introduce the melt of the degassing box into the filter box to filter out impurities in the melt. The step of filtering out impurities in the melt also includes: putting the ceramic foam filter plate into the filter box and pressing the sealing gasket around the filter plate; preheating the filter box and filter plate evenly for 15min~30min to make it close to the melt temperature. Preheating uses electric or gas heating.
5. Introduce the melt to the neutral plate of the alumina fiber flow box through the trough and launder to control the liquid level of the melt in the front tank. Also includes:
Brush the talc powder in the mud of the front tank flow tank, dry and heat to 400°C~500°C; clean the residue in the static furnace; control the height of the melt liquid level in the front tank flow tank. The bottom side of the front box communicates with the bottom of the front tank flow channel through a straight tube; the front box has ladle shroud on the liquid surface, the ladle shroud scale guide bar is provided with a cursor scale and a positioning slide sleeve, and the float is fixed and positioned on the outer periphery. The sliding sleeves are connected, and the positioning sliding sleeves are connected to the graphite fluorescent head at the straight pipe on the bottom side of the front box through a lever.
6. The melt is introduced into the twin roll continuous casting and rolling machine from the ceramic fiber caster tip and continuously cast into a strip.
There is a gap of 2mm~3mm between the upper lip and the lower lip of the casing tip and nozzle and the rolls of the twin roll continuous casting and rolling machine. The castertip ear is placed on both ends of the upper lip and lower lip of the feeding nozzle. In order to enhance the smoothness of the casting tip ear, the edge of the ear is smeared with graphite powder, which solves the problem of large cracks on the edge of the blank.