1. Sundries attached to the surface of the ingot
2, the ingot composition is segregated, and there are a lot of segregated floats on the surface
3. Once the ingot has not been homogenized or the homogenization effect is not good, there will be a certain amount of hard metal particles in the ingot. When metal flows through the working belt during extrusion
These segregation floats or hard metal particles adhere to the surface of the working belt or cause damage to the working belt, and ultimately cause scratches on the surface of the profile.
4. There is debris on the mold cavity or working belt, and the hardness of the working belt of the mold is low, so that the surface of the working belt is injured during extrusion and the profile is scratched;
5. There are bare metal on the discharge track or swing bed, or there are hard inclusions in the graphite strip. When it comes into contact with the profile, it scratches the surface of the profile;
6. When the fork rod sends the profile from the discharge rail to the swing bed, the profile is injured due to the excessive speed;
7. Manually drag the profile on the swing bed to cause abrasions;
8. In the course of transportation, the profiles are rubbed or squeezed to cause damage.