Common problems with
aluminum plates and causes
1. The surface bubbles
2. The quality of the perforation is not good. The hydrogen content of the ingot is loose. The uneven surface of the ingot surface is dirty to the east and is not cleaned before the furnace. After the corrosion, the cast block and the coated
aluminum plate surface have erosion residue traces; The heating time is too long or the temperature is too high. When the first weld is rolled, the emulsion is not closed, and the emulsion flows under the
aluminum plate.
3. The cracking of the cast block is too large, and it is cracked from the end of the ingot. The heating temperature is too high or too low.
4. The mechanical property is not qualified and the heat treatment system or the heat treatment equipment is not normal. Quenching fashion material is large, salt bath tank temperature is not enough fashion furnace, thermal insulation time is not enough, did not reach the specified temperature is out; The heat treatment system or test method adopted in the laboratory is not correct; The sample size is incorrect and the sample surface is damaged.
5. The casting quality is not good, there are metal or non-metal residue in the
aluminum plate.
6. The tear lubricant composition is not qualified or the emulsion is too strong, the plate and the roll can slide, the metal deformation is not uniform; The rolling rate is not controlled, and the pressure is too large. Excessive rolling speed; The tension of the drum is not correct and the tension is unstable. Poor annealing quality; Insufficient metal plasticity; The roller type control is not correct, the metal internal stress is too large; Edge of hot rolled drum; When rolling, the lubrication is not good. The coil is not positive, and the tension stress is generated on the side of the plate, and the pressure is produced. The edge is produced by a small tear. After repeated rolling, it continues to expand from the crack and even tear. In the finishing time, the clamping clamps are unevenly or unevenly, or the plates have split edges, which can cause tearing when stretching. When quenching, the hood is not good or too tight, so that the plate fracturing, stretching and straightening can cause tearing.
7. It is not correct to adjust the amount of overpressure. Failure or improper use of thickness gauge; Roller type control is not correct.
8. Pressing (folding) roller type is incorrect, for example, the bearing of the press light machine is hot, so that the roll end of the roll is swollen, and the result is thin on both sides of the plate. The front plate wave is too large, so that the pressure light is too large, and the pressure is broken. When the laminate is pressed light, it is easy to produce pressure. The plates are thick on both sides and easy to produce pressure.
9. Non - metal rolling mill roll, roller, scissoring machine and so on not clean, the processing of the dirt in the
aluminum plate car, through rolling and forming; The parts of the roller, guide roller, three-roll straightener and coiler of cold rolling mill are not clean, and the dirt is pressed in. The rolling oil nozzle is blocked or the pressure is low. The emulsion replacement is not timely, the aluminum powder is not clean and the emulsion tank is not cleaned.
10. The high temperature instrument of overheat treatment equipment is not accurate; The temperature is not uniform in each area of the electric furnace; In the absence of proper heat treatment system, the metal heating temperature reaches or exceeds the metal overheat temperature; If the loading is not positive, the area near the heater may produce local overheat.
11. When the metal is pressed into the heating process, the metal debris falls on the plate and is formed after rolling. When hot rolled, the edge of the roll is less, and the metal on the crack is dropped on the belt plate. The cutting edge of the disc is not good, the edge of the belt is burr, and the compressed air does not blow the metal scraps on the surface of the belt plate. After the roll is glued, the
aluminum plate is pressed onto the strip. The ruler was clamped tightly and the scraped crumbs fell on the board.
12. The wave roller type adjustment is not correct, the original roller type is not suitable; Failure or improper use of panel control system; The raw material of cold rolled raw material or the convex in the section; The selection of pressure rate, tension, speed and other technological parameters is improper. All kinds of straightening machine adjustment is not good, straightening roll gap is not consistent, make sheet thin side produce wave; For stretch straightening and bending straightening machine, the elongation rate is not chosen properly.
13. After hardening, washing and drying, the surface residual acid, alkali or nitrite traces will be corroded after a period of time. Improper storage of board, water drop on board; In the process of processing, the auxiliary materials of contact products, such as oil, rolling oil, emulsion, packaging oil, etc. contain water or alkaline, which may cause corrosion; Too high temperature or bad packaging during packing, damaged during transportation.
14. Cut hot rolling mill roll, guide plate to adhere to aluminum, make hot pressing plate with scratch; The guide plate of cold rolling mill, pinch roller, etc. The finishing line is cut by the guide road; When the finished product is packed, it is not properly carried.
15. When the element diffuses annealing and quenching, the heat treatment system is not properly implemented, and the heating time can be prolonged or the heat preservation temperature can be increased. Too many times of annealing and quenching; The tail of hot rolled or pre-cut machine is not required to cut the head in accordance with the process specification, causing the aluminum layer to be unqualified. The wrong use of aluminum plate, the use of aluminum plate is too thin.
16. Too thick for the same reason as 7 "too thin".
17. It is easy to cause chafing when it is not careful. The conveyor belt is not positive, and the slanting plate is brought forward when rolling, so that the belt plate and the roll can produce relative friction. The tension is not correct when the volume is rolled, the tension is small when the roll is taken, the tension is large when the roll is open, and the roll pulls the roll tightly to make the plate stagger. There is too much oil in the lubricating oil, which is different from the residual oil on the drum after rolling.
18. The disc shear spacing is adjusted too narrow after narrow shear; Insufficient spare capacity of hot coarse rolling; When the hot finishing mill is adjusted, it is not very good to consider the amount of cold shrinkage and shear allowance during shear.
19. In the short cut, the ruler or equipment malfunction.
20. The two ends of the roller are different at the end of the roller. The guide tape board is not positive, and the strip is extended on both sides. Hot mill roll preheating is not good, roll shape is not correct; The emulsion jet is uneven or the nozzle is blocked; When the press is rolled, the plate is not in alignment.
21. The heating temperature is too low, the crack edge produced when hot pressing is not cut off, and the edge is expanded after cold rolling. The edge of the hot roll is too small, which may cause the splitting edge; Too large or too small; The casting gate is not cut off, it will crack when hot rolling; Cut the sides unevenly, cutting too little, may produce a split edge; The annealing quality is not good, the metal plasticity is not enough; The
aluminum sheet is not properly placed, so the side is not completely aluminum.
22. The crack or heating temperature is too high or too low; The rolling rate inappropriately causes compression.
23. Shrinkage hole casting quality is not good.
24. The emulsion is not clean, or the new emulsion is uneven.
25. When the emulsion mark is rolled, the emulsion is not blown clean, so that the emulsion is involved in the cylinder; The hot precision rolling temperature is too low, the emulsion concentration is too high; There is water in the duct, and it blows on the strap with the air.
26. The aluminum laminated
aluminum sheet is not properly placed, and the metal clad aluminum plate and ingot are staggered when hot and rough rolling. In hot rough rolling, the cast block is not properly delivered; It is too small to weld when the welding is rolled. It is too large for the side aluminum casting roll. The cutting edge of finishing shear and hot finishing is not uniform, and too little is cut.
27. To be hit in the process of carrying or parking. When cold rolling or annealing, the card is not good, and the annealing material is not clean, there are metal objects or protrusions; Cold rolled into hard metal slag or other hard stuff.
28. In the cold rolling of the pine tree, the pressure is too large, and the metal is sliding due to the large friction force between the rolls. The concentration of rolling liquid is too large, and the fluidity is not good, and it cannot be distributed evenly on the plate surface, and the pine tree will be produced after rolling. The thickness display instrument fails; Cold rolling tension is too small.
29. The wave or sickle shape is produced by pressing the indentation hot rolling. When it is cut through the tail feeding roller, scissors, three rolls and so on, and the cutting of the guide plate of the rolling machine, it is crushed; The quantity of annealing charge or removal is more, so that the drum is loose; Hot rolled road aluminum scratch strip, after cold rolling production; The road of cold rolling mill, three rollers, five rollers appear to be viscous or roiling, scratches, abrasion
aluminum plate, through rolling production; The tension of cold rolling and hot rolling is not stable, the tension size does not match, or the loading and unloading rolls are not careful, so as to make the laminates between the layers.
30. After the nitrite mark quenching, the washing is not clean, and the surface of the plate is not clean.
31. The roll of a cold rolling mill is coated with metal residue, or the roll is printed on the board. The straightening and rollers are sticky with metal scraps, not clear rollers or rollers. Before straightening, the metal residue falls on the plate and is caused by straightening.
32. The adhesive aluminum is caused by the uncleanliness of the straightener roller on the shearing machine. All multi-roll straightening machine is easy to stick to the plate surface; When hot rolling or cold rolling, the roll is sticky.
33. Break the sheet and handle with carelessness.
34. Kneading and quenching of the plate is too big and scratch each other; Careless loading and unloading, or loading too much, making the plates misbehave each other.
35. The tension control is improper when the horizontal wave cold rolled sheet, so that the inside turns in the drum make the nest. Stop in the middle of the rolling process.
36. The thickness of the aluminized layer is too high. The tail of hot rolled tail or preshear head is too small; Aluminum plate is used wrong; The alkaline wash time is too long.
37. Residual rolling oil on the plate after the oil trace.
38. Slip line plate during stretching for stretching quantity is too big a slip line (45 °) along the direction.
39. When the water mark is quenched, it is not cleaned and pressed to the plate.
40. The surface is not bright roller, roller, straightening roller is not enough, the lubrication performance is not good, too dirty.
41. Small black spots in the process of hot rolled plate, due to the high temperature emulsion decomposition, decomposition product and make the roll because of bad lubrication in the process of rolling friction and aluminum and the aluminum powder at high temperature interaction, produce "small black spots" in the emulsion, after rolling and pressure to the
aluminum plate on the surface, form small black spots; Emulsion stability is bad, not clean, bad lubricity, prepared with hard water, uneven emulsion injection on the roll, and channel is not clean, roller, cooking, tubing, fuel tank is not clean and easy to produce "small black spots".
42. Due to the poor quality of the milling surface, the surface oxidation of the cast block is heated, and the quality of the cast block is not good enough to form a strip or block.
43. In the process of rolling, uneven deformation is produced in the end or side of plate, and it is spread when rolling.