11. In the process of metal pressing and heating, the metal scraps fall on the strip and are formed after rolling; during hot rolling, the number of roll edges is few, and the cracked metal falls on the strip; the quality of the disc shearing edge is not good, and the edge of the strip is not good. There are burrs, and the compressed air does not blow off the metal chips on the surface of the belt plate; after the roller sticks to the aluminum, press the sticky aluminum block on the belt plate; the guide ruler is too tight, and the scraped scraps fall on the plate.
12. The wave roll shape is not adjusted correctly, the original roll shape is not suitable; the shape control system is faulty or improperly used; the original shape of the cold rolled wool is poor or the convexity in the section is too large; the selection of process parameters such as reduction ratio, tension and speed Improper; various types of straighteners are not well adjusted, and the gap between the straightening rollers is inconsistent, causing waves on the thin side of the sheet; for stretch-straightening and stretch-bending straighteners, the elongation rate is not selected properly.
13. After quenching, washing and drying, the corroded plate will be corroded after a period of time when traces of acid, alkali or nitrate remain on the surface; , Auxiliary materials in contact with the product, such as kerosene, rolling oil, emulsion, packaging oil, etc. contain moisture or are alkaline, which may cause corrosion; the temperature of the coil is too high during packaging, or the packaging is not good, and it is damaged during transportation. .
14. The roller table of the hot rolling mill is scratched, and the guide plate sticks to aluminum, so that the hot-pressed plate is scratched; the guide plate and the pinch roller of the cold rolling mill have protruding sharp corners or stick to aluminum; the finishing machine is scratched by the guide path; the finished product When packing, the lifter is not properly lifted.
15. During element diffusion annealing and quenching, the heat treatment system was not implemented correctly, and the heating time or holding temperature was unreasonably extended; the number of annealing and quenching was too many; It is caused by the unqualified aluminum-coated layer of the plate; the aluminum-coated plate is used by mistake, and the aluminum plate is too thin.
16. Too thick The reason is the same as 7 “too thin”.
17. If you are not careful when hoisting and transporting the reel, it is easy to cause the reel to be scratched; if the feeding strip is not correct, the skewed strip will be straightened during rolling, causing relative friction between the strip and the roll; Correct, the tension is small when coiling, and the tension is large when uncoiling, the rollers tighten the reel to cause dislocation between the plates; the lubricating oil contains too much sand and oil, and the residual oil on the reel after rolling is different. There is very little slippage between the rings causing chafing.
18. Too narrow The disc shear spacing is adjusted too narrow during shearing; the hot rough rolling allowance is insufficient; when the hot finishing rolling disc shear is adjusted, the cold shrinkage and the shear allowance during shearing are not well considered.
19. Too short Improper sizing or equipment failure when cutting.
20. The roll gap value at both ends of the sickle-shaped hot rolling mill roll is different; the guide ruler feeds the strip plate incorrectly, and the two sides of the strip plate extend differently; the hot rolling mill roll is not preheated well, and the roll shape is incorrect; the emulsion spray is uneven or the nozzle is blocked; The sheet was misaligned during calender rolling.
twenty one. The heating temperature of the ingot with cracked edge is too low, and the cracked edge generated during hot pressing is not completely cut off, and the cracked edge expands after cold rolling; if the edge amount of the hot roll is too small, cracked edge may occur; the reduction rate is too large or too small; If the gate part of the ingot is not cut off, the edge will be cracked during hot rolling; when the edge is trimmed, both sides are cut unevenly, and one side is cut too little, which may cause cracked edges; the annealing quality is not good, the metal plasticity is not enough; the aluminum clad plate is not placed correctly , so that one side is not completely covered with aluminum.
twenty two. Cracks The ingot itself is cracked or the heating temperature is too high or too low; inappropriate rolling rate causes compression.
twenty three. Shrinkage holes Poor quality ingot.
twenty four. White spots The emulsion used for cold rolling is not clean, or the new emulsion is not stirred evenly.
25. Emulsion marks The emulsion is not blown out during rolling, so that the emulsion is involved in the drum; the hot finishing temperature is too low, and the emulsion concentration is too high; there is water in the air duct, which is blown onto the strip with the air.
26. The dislocation of the clad aluminum layer The clad aluminum plate is not placed correctly, and the dislocation between the metal clad aluminum plate and the ingot occurs during hot rough rolling; the ingot is not sent correctly during hot rough rolling; the reduction amount during welding rolling is too small, no Welding; too much roll edge of aluminum-coated ingot on the side; uneven trimming amount of trimming shearing and hot finishing rolling, and too little trimming on one side.
27． Dimples (Bumps) Plates or reels are collided during handling or parking; the clamps are not played well during cold rolling or annealing, and the annealing material is not clean, with metal objects or protrusions; Metal slag or other hard things.
28. When the pine dendritic cold rolling is performed, the reduction amount is too large, and the metal slips between the rolls due to the large friction force, so it is too late to flow; Afterwards, it will produce a pine tree shape; the thickness display instrument is faulty; the cold rolling tension is too small.
29. Pressed through the scratches, hot rolling produces waves or sickle shapes, which are scratched when they pass through the rear feed roller, scissors, three rollers, etc., and the scratches on the guide plate of the heat rolling machine, and are pressed over; annealing is charged or transported many times , to loosen the reel layer; the hot-rolled road sticks to the aluminum and scratches the strip, which is produced after cold rolling; the road of the cold-rolling mill, the three-roller and five-roller are sticky or fail to rotate, and the aluminum plate is scratched and scratched. It is produced by rolling; the tension of cold rolling and hot rolling is unstable, the tension does not match, or careless when loading and unloading the coil, so that the interlayer staggers and scratches the surface of the plate.
30. Saltpeter marks After quenching, it is not clean, and there are saltpeter marks on the surface of the plate, and it is not clean before calendering.
31． Imprints The cold rolling mill rolls are stuck with metal residues, or the rolls have imprints on the plate surface; metal residues are stuck on the straightening and rollers, and the rolls are not cleaned or the cleaning is incomplete. Metal residues fall on the plate before straightening, which is caused by straightening.
32． Sticking to aluminum on the shearing machine row is caused by unclean rollers of the straightening machine; all multi-roll straighteners during finishing are easy to stick to the surface of the sheet; during hot rolling or cold rolling, the roll sticks to aluminum, causing sticking to the strip. .
33. Broken Sheets are handled carelessly.
34． Kneading and scratching After quenching, the bending of the plates is too large, and they are scratched with each other; careless loading and unloading, or too much loading, make the plates stagger each other.
35． Transverse wave Improper tension control during cold rolling of the sheet, which causes the inner turns of the reel to cause nests during unloading; stop in the middle of the rolling process.
36． The thickness of the aluminum cladding layer is unqualified. The hot-rolled welding reduction is too large; the amount of the hot-rolled tail or the pre-shear head is too small; the aluminum-clad plate is used incorrectly; the alkali cleaning time is too long.
37． Oil streaks Rolling oil remains on the plate after cold rolling.
38． Slip line The direction of the slip line (45° along the way) that occurs when the plate is stretched too much.
39． Water marks were not wiped clean after quenching, and were pressed on the plate during calendering.
40. The surface is not bright. The smoothness of the roll, calender roll and straightening roll is not enough, the lubrication performance is not good, and it is too dirty.
41． In the process of hot rolling sheet, due to the decomposition of high temperature emulsion, the decomposition product interacts with the aluminum powder generated by the friction between the roll and the aluminum plate due to poor lubrication during the rolling process, resulting in a mixture of “small black spots”. In the emulsion, after rolling and pressing on the surface of the aluminum plate, small black spots are formed; the emulsion is not stable, not clean, and has poor lubricity. When it is prepared with hard water, the emulsion is sprayed unevenly on the roller, and the roller table is not clean. If the roller table, trench, oil pipe and fuel tank are not clean, it is easy to produce “small black spots”.
42． Skinning Due to the poor quality of the milling surface, the surface of the heated ingot is oxidized, and the quality of the ingot itself is not good to form strips or lumps of skinning.
43． Delamination During the rolling process, uneven deformation occurs at the end or edge of the strip, and it spreads during continuous rolling.