Aluminum sheet and strip manufactured into surface defects

Aluminum sheet and strip manufactured into surface defects

(1) Skinning

Definition and characteristics: the surface of the sheet and strip of the local layer. The layer is thin, broken and turned up.

Main causes: long heating time, severe oxidation of the surface.

(2) Cracking

Definition and characteristics: plate and strip surface cracking phenomenon.

The main causes: the heating temperature of the cast block is too high; the processing rate is too large.

(3) Cracked edge

Definition and characteristics: plate, strip edge rupture, serious jagged.

Main causes: low casting block temperature, poor metal plasticity; improper roll control, so that the plate, strip edge tensile stress; incomplete side cladding aluminium; excessive processing rate; improper roll edge process; improper adjustment of winding tension during cold rolling.

(4) Delamination

Definition and characteristics: The plate cross-section produces cracks parallel to the surface of the plate and extending along the direction of rolling.

Main causes: improper distribution of hot rolling passes, too much pressing down; uneven heating of ingots or too high or low heating temperature.

(5) Scuffing

Definition and characteristics: due to the existence of debris between the plate and strip layers or aluminum powder and plate surface contact, material between the prism and surface, or surface and surface contact after the relative sliding or misalignment and in the plate, strip surface caused by the bundle (or group) distribution of scars.

The main reasons: plate, strip in the process of production and guide road, equipment contact friction; cold rolled volume end face is not flush, in the vertical furnace annealing flip layer and layer between the wrong movement; uncoiling when the layer between the wrong movement; coil loose roll.