Method for manufacturing of strips and rolling mill line

Method for the manufacture of strips of stainless steel, comprising cold rolling of a strip which in a foregoing process has been manufactured through casting a melt to form a cast strip and/or has been hot rolled, wherein the cold rolling is performed in a rolling mill line which comprises, in an initial part of the line, at least two initial cold rolling mills in series, after said initial cold rolling mills at least one annealing furnace and at least one pickling section and, in a terminating part of the line, at least one further cold rolling mill, wherein the cast and/or hot rolled strip, which is dark colored by oxides on the surfaces of the strip, with the dark colored oxides remaining on the surfaces of the strip, first is cold rolled in at least one of said initial cold rolling mills so that the thickness of the strip is reduced totally by 10-75%, then the strip is annealed and pickled in said annealing and pickling sections and is cold rolled in said at least one further cold rolling mill reducing the thickness by max 1.5%, and then the strip is fed once more in the same direction through the same rolling mill line, at which the strip is rolled in at least three initial cold rolling mills, reducing the thickness totally by 30-75%, before the strip again is annealed and pickled.

Method for the manufacture of strips of stainless steel, comprising hot rolling in an initial process and subsequently cold rolling in a rolling mill line, said hot rolling being stopped when the strip thickness has been reduced to a thickness between 2.5 and 6 mm, said hot rolled strip being cooled from a final hot rolling temperature through quenching at a cooling rate of at least 15° C./s to below 500° C., said strip at the subsequent cold rolling being passed twice in the same direction through said cold rolling line which comprises at least two cold rolling mills in an initial part of the line and, after said initial cold rolling mills, at least one annealing section and at least one pickling section, said strip, as it for the first time passes the at least two cold rolling mills in the initial part of the line, being rolled with the dark colored oxides remaining which oxides the strip has obtained in the hot condition of the strip during said initial process.

Method for the manufacture of strips of stainless steel, comprising cold rolling of a strip which in a foregoing process has been manufactured through casting a melt to form a cast strip and/or has been hot rolled, said cast and/or hot rolled strip, which is dark colored by oxide scales on the surfaces of the strips, remaining from the foregoing manufacturing of said cast and/or hot rolled strip, being cold rolled in one or more consecutive cold rolling passes reducing the strip thickness by 10-75%, forming cracks in said oxide scales, annealing the strip in a furnace having a furnace atmosphere which contains max 10 vol-% oxygen, and pickling the strip.

Method for the manufacture of strips of stainless steel, comprising cold rolling of a strip which in a foregoing process has been manufactured through casting a melt to form a cast strip and/or has been hot rolled, wherein the cold rolling is performed in a rolling mill line which comprises, in an initial part of the line, at least two initial cold rolling mills in series, after said initial cold rolling mills at least one annealing furnace containing a furnace atmosphere obtainable by heating the furnace by means of a burner which consumes a liquid or gaseous fuel which is combusted by means of a gas which contains at least 85 vol-% oxygen and at most 10 vol-% nitrogen;

• after the annealing furnace at least one pickling section and, in a terminating part of the line, at least one further cold rolling mill, the cast and/or hot rolled strip, which is dark colored by oxides on the surfaces of the strip, initially is cold rolled in at least one of said initial cold rolling mills with the dark colored oxides remaining on the surfaces of the strip, so that the thickness of the strip is reduced by totally 10-75%, said strip then being annealed in said annealing furnace containing said furnace atmosphere and pickled in said at least one pickling section.

Rolling mill line for cold rolling stainless steel strips, comprising initial cold rolling strips having dark colored, oxidic surfaces, obtained at a foregoing manufacturing process through strip casting and/or hot rolling of stainless steel strips, further comprising, in an initial part of the rolling mill line, a cold rolling line comprising at least two cold rolling mills in series, in the terminating part of the line, at least one terminating cold rolling mill, and at least one annealing section and at least one pickling section between said initial cold rolling section and said terminating cold rolling mill.