Reasons for defects on the surface of aluminum plate:

1. Folding (folding) roll type is not correct, such as calender bearing heating, so that the two ends of the roll swell, the result of the pressure out of the plate thick on both sides of the thin; Before the plate wave is too large, so that the amount of light is too large, resulting in compression folding; When the sheet is calendering, it is easy to fold when it is not feeding properly. The thickness difference between the two sides of the plate is large, easy to produce pressure folding.

2. Surface bubbles: ingot surface convex and concave uneven place dirty east, not clean before loading; After corrosion washing, there are residual traces of corrosion washing on the surface of cast block and aluminum plate; If the heating time is too long or the temperature is too high, the surface of the cast block will be oxidized.

3. Casting block cracking: hot rolling pressure is too large, from the end of the ingot cracking; The casting heat temperature is too high or too low.

4. Casting ingot slag casting quality is not good, the plate with metal or non-metallic residue.

5. Too thin pressure adjustment is not correct; Thickness gauge failure or improper use; Incorrect roll profile control.

6. The casting block cracking hot rolling pressure is too large, from the end of the ingot cracking; The casting heat temperature is too high or too low.

7. The mechanical properties are not qualified, the heat treatment system is not properly implemented or the heat treatment equipment is not normal, and the air circulation is not good; Quenching fashion material, salt bath temperature is not enough fashion furnace, holding time is not enough, did not reach the specified temperature is out of the oven; The heat treatment system or test method used in the laboratory is incorrect; The size and shape of the sample are incorrect and the surface of the sample is damaged.

8. Tear lubricating oil composition is not qualified or emulsion is too thick, there is sliding between sheet and roll, metal deformation is not uniform; Did not control the rolling rate, the amount of pressure is too large; Excessive rolling speed; Drum tension adjustment is not correct, tension is unstable; Bad annealing quality; Insufficient metal plasticity; Incorrect control of roll shape causes excessive internal stress of metal; Hot rolled drum crack edge; Rolling lubrication is not good, plate and roll friction is too large; The roll is not straight, the strip side produces tensile stress, one side produces compressive stress, so that the edge produces a small crack, after many rolling, from the crack continues to expand, and tear; When finishing, the stretching machine clamp is not straight or uneven, or the plate has a split edge, it will cause tearing when stretching; When quenching, the chain is not good or too tight, so that the plate fracturing, tensile straightening caused tear.