2. Technical objectives and problems

2.1 Stripping

Hot-rolled strips are covered with a layer of oxides known as scale, and the main aim of the pickling operation is to remove this layer. Pickled coils are most often destined for cold rolling, or used as they are. Only the first case will be considered here.

Preparing coils for cold rolling poses the following problems:

• obtaining an oxide-free strip surface, as scale would interfere with cold rolling:

  • as it elongates much less than steel, it would become embedded in the metal, piercing it even in thin layers, and significantly reducing its stamping capabilities,

  • abrasive, because harder than the base metal, it would rapidly destroy...