First, non-metallic pressed into
Definition: non-metallic debris pressed into the plate, strip surface. The surface is obvious point or long yellow and black defects.
The main reason: rolling process equipment conditions are not clean; rolling process lubricant is not quiet; process lubricant injection pressure is insufficient; slab surface scuffing.
Second, abrasion
Definition: due to the object between the prongs and surface, or surface and surface contact after the occurrence of relative sliding or misalignment in the plate, with the surface caused by a bunch (or group) distribution of scars.
The main reason: plate, strip in the processing and production process with the guide, equipment contact, resulting in relative friction and caused by abrasion; cold rolled volume end face is not flush, in the vertical furnace annealing flip produced by the wrong movement, layer and layer of abrasion; cold rolled tension is not appropriate, uncoiling produced between the layer of the wrong movement and abrasion; finishing acceptance or packaging operation improperly produced between the plate sliding and caused by the abrasion.
Third, bruises
Definition: Aluminum plate, aluminum coil and other objects collision in the plate, with the surface or end face of the scratch, and most of the depression in the margins of the presence of extruded metal.
The main reason: plate, volume in the handling or storage process and other objects collision; plate, volume in the annealing frame or chassis with other protruding objects top hit and produce.
Fourth, the edge of the warping
Definition: After rolling or shearing, the strip edge warping.
The main reason: rolling under the amount of pressure is too large; rolling lubricant distribution is not uniform; shear when the shear edge is not properly adjusted.
Fifth, fracture
Definition: the deformation of the plate after bending creases.
The main reason: multi-roller straightening machine feeding incorrectly; sheet in the flip or handling force imbalance; on the stack of sheet force imbalance.
Six, collapse volume
Definition: serious deformation of the core, roll shape is not round.
The main reason: improper tension in the process of curling; external compression; low core strength; no core rolls produced by annealing.
Seven, wrong layer
Definition: irregular misalignment between the strip end layer and layer, resulting in end surface unevenness.
The main reasons: billet uneven; rolling mill uncoiling, coiling tension control is not appropriate; the amount of uneven under pressure, sleeve stringing; flattening rollers are not properly adjusted; coiling process, the alignment system is abnormal; roll system parallelism is not good.
Eight, tower
Definition: the tape roll layer and layer to one side of the formation of tower-shaped offset.
The main reason: the incoming material board shape is not good, tension control is not appropriate; coiling alignment control system is abnormal; coiling with the head of the bonding is not firm.
Nine, loose volume
Definition: When coiling and uncoiling, there is loosening between layers, and in serious cases, the whole roll is affected.
Main reasons: uneven or too small tension in the process of coiling; uncoiling pressure roller is too small; steel belt or card is not firm, when lifting.