Aluminum melt temperature. If the local temperature is too high liquid aluminum melt burnt, it will result in the production of sticky rolls and other defects. Occurs sticky roller, slab thickness increases 0.20.4mm, this time rolling force increases, it will cause a horizontal, vertical exceeded with plate poor. To produce the desired flatness, it is necessary to ensure that the roller bearing is intact, the statistics accumulated value of the bearing clearance, minimizing bearing replacements, cooling water between 0.35 a 0.4MPa; regular cleaning inside the tank roll; roll gap the process parameters, roll crown, slab thickness coherence; adjustment to control the temperature of molten aluminum, molten aluminum to prevent over-burning.
Surface corrosion
(1) Graphite emulsion spray reasons. April 1994 I roll casting plant there had been large-scale corrosion, corrosion occurs in a place with a graphite deposit, the more severe and the more graphite deposit where corrosion. Deposited on a slab of graphite having a capillary condensation effect, where it is easy to dew and easily lead to oxygen concentration cell corrosion, and because the active material is graphite, which deeply film of water or moisture can improve the film membrane conductance rate, so accelerated corrosion.
(2) temperature, humidity, water impact. At room temperature electrochemical corrosion of metals is a process. The main components of causing metal corrosion in the atmosphere are water and oxygen. Water or moisture may generate various strip corrosion and temperature difference between the temperature of the strip corrosion and corrosion caused by changes (or cold volume effect), it has been confirmed by many manufacturers.
(3) Fe content, the roll surface cracks, sticky roller impact. Production was found, Fe content and the roll surface cracks, the board caused by sticky roller rough, does not cause corrosion. But after corrosion, these factors will accelerate corrosion. You can take the following measures to prevent the occurrence of corrosion: When strict emulsion concentration ratio of graphite, graphite emulsion spray evenly to ensure the roll surface, to avoid casting plate graphite deposit, you can not adjust the gun nozzle aligned graphite rolls; casting roll should be a within weeks of the cold rolling mill rolling (cold rolled coil surface with a layer of film, can prevent the aluminum damp); avoid hot coil packing; casting roll grinding time, to avoid the production of sticky roll phenomenon; avoid casting roll for a long time in the air hot and humid environment, strengthen the rain and moisture during storage and transportation.
