1. Before using the rolling mill
1. The roll surface of the roll should be smooth enough to prevent sticking when the vertical plate is installed. It is recommended that the surface roughness Ra ≧ 0.8.
2. During lifting or handling, the roller surface should be strictly protected and carefully guarded against collision with other objects.
3. When storing, the roller neck should be supported and the roller surface should be protected. It is strictly forbidden to directly contact the roller surface with the ground or other hard objects.
4. When standing, first use a soft object to wipe off the oil stain on the roller surface, and then use a flame (acetylene or liquefied gas) to evenly heat the roller surface to make its temperature reach 50-60 ℃. The warm-up time is generally about 2 hours.
2. Casting and rolling machine in use
1. Product specifications should follow the principle of "first wide and then narrow".
2. Evenly lubricate the roller surface with liquefied gas flame or graphite emulsion to make the roller surface adhere to a layer of carbide to prevent the aluminum plate from sticking to the roller.
3. In order to shorten the non-working time, when the product specification needs to be stopped, the circulating water should be turned off as soon as possible after the aluminum liquid leaves the roll surface, and then stopped to ensure the roll surface temperature. When the downtime is longer, the roller surface needs to be preheated according to the requirements of Article 4 of the first paragraph.
4. It is strictly forbidden to remove the sticky aluminum from the roller surface with hard and sharp instruments. Only use fine gauze or graphite blocks to remove the aluminum adhesion in the circumferential direction, or sand the roller surface with sandpaper. The gauze particle size is above 120 mesh.
5. Once the roller surface is damaged, the production should be stopped immediately, and the roller surface should be re-ground to prevent the roller sleeve from bursting suddenly.
6. If the crack can be clearly seen with the naked eye, it indicates that there is an open crack, and the length of the crack in the circumferential direction is greater than 30mm or the length of the transverse crack is greater than 15mm, then production must be stopped, the rolls must be removed, and magnetic particle inspection should be carried out in each serious area The aluminum on the surface of the flaw detection site must be cleaned), and the flaw detection results are laminated. Then re-grind the roller surface to prevent the roller sleeve from bursting due to continued use. All magnetic particle inspection and coating departments shall make detailed records and keep spare sets.
7. The operator should pay attention to observe the micro-cracks on the roller surface at any time, and make a detailed handover record.
8. In case of unexpected accidents (such as power failure, power cut, etc.), the water source must not be turned off to prevent the roller sleeve from bursting due to local heating and high temperature. The correct method is to turn off the water source after all the molten aluminum leaves the roller surface.
9. Requirements for cooling water channel: Keeping the cooling water channel in the roll smooth is a prerequisite for casting and rolling production. During the production process, the quality of the cooling water must be regularly checked and treated to meet the requirements of the cooling water:
(1) Water hardness: the total hardness is not more than 7 (add algaecide, slow release agent and scale inhibitor in water)
(2) PH value: 6-8
(3) Suspended matter: not more than 50PPM
(4) Water pressure: 0.4-0.6Mpa
(5) Water temperature: generally controlled at 15-28 ℃
