1. through the pores
Casting quality is not good.
2. Surface bubbles
The ingot has a high hydrogen content and loose tissue; the surface of the ingot is uneven and the surface is dirty, and there is no wiping before the furnace. After etching, the residual surface of the ingot and the aluminum plate is etched; the heating time is too long or the temperature Too high, the surface of the cast block oxidation; the first welding rolling, the emulsion nozzle is not closed, the emulsion flow to the package under the aluminum plate.
The amount of pressure during hot rolling is too large to crack from the end of the ingot; the heating temperature of the ingot is too high or too low.
4. Mechanical performance is not qualified
There is no proper implementation of the heat treatment system or heat treatment equipment is not normal, the air circulation is not good; quenching and loading materials, salt bath temperature is not enough time furnace, holding time is insufficient, did not reach the required temperature that is baked; laboratory use of heat treatment system or test method Correct; sample size is not correct, the specimen surface is destroyed.
5. Ingot slag
Casting quality is not good, the board is covered with metal or non-metallic residue.
Lubricating oil composition is not qualified or the emulsion is too strong, between the plate and roll sliding, metal deformation is not uniform; no control of the rolling rate, the amount of pressure is too large; rolling speed is too large; roll tension adjustment is not correct, Tension is not stable; annealing quality is not good; metal plastic enough; roll control is not correct, so that the metal stress is too large; hot rolled reel edge; rolling lubrication is not good, strip and roll friction is too large; Is not correct, with the plate side of the tensile stress, while the production of compressive stress, so that the edge of a small gap, after repeated rolling, from the gap to continue to expand, as well as tear; finishing stretch machine jaw clamp is not correct or not Are, or the board has cracked edge, stretching will cause tear; quenching, pocket pocket pocket bad or too tight, so that plate fracturing, stretching straightening caused tear.