Method for manufacturing of stainless steel strips
AssigneeOutokumpu Oyj
InventorsEsa Puukko, Leeni Aula
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Abstract
The invention relates to a method for manufacturing strips of stainless steel, comprising hot rolling in an initial process (A) and subsequently cold rolling in a cold rolling line (B). The hot rolling is stopped when the strip thickness has been reduced to a thickness between 2.0 mm and 6.5 mm. The subsequent cold rolling is passed at least one time through said cold rolling line, which comprises in the following order: At least one cold rolling mill (11-13) in the initial part of the line, at least one annealing section (17), a scale breaking step (21), a shot blasting step (23) and at least one pickling section (26, 27) utilizing a mixture of nitric acid HNO3, hydrofluoric acid HF and optionally sulphuric acid H2SO4.
Claims10
A method for manufacturing strips of stainless steel, comprising:
- hot rolling a strip comprising stainless steel in an initial process, wherein the hot rolling is stopped when the strip thickness has been reduced to a thickness between 2.0 and 6.5 mm, and wherein during the hot rolling, the hot rolled strip is quenched from a final hot rolling temperature to a temperature above 650° C. and below 700° C.;
- and
- passing the hot rolled strip through a cold rolling line to produce a cold rolled strip, wherein the cold rolling line comprises, in the following order:
- at least one initial cold rolling mill;
- at least one annealing section;
- a scale breaking section;
- a shot blasting section;
- at least one pickling section utilizing a mixture of nitric acid HNO3, hydrofluoric acid HF, and optionally sulphuric acid H2SO4;
- and
- at least one terminating cold rolling mill,
- wherein the hot rolled strip entering the at least one initial cold rolling mill is covered with ductile, dark coloured oxides formed during the hot rolling that substantially remain on the strip after the strip passes through the at least one initial cold rolling mill.
Dependencies are inferred from the claim text.