Producing a rolled steel strip used for the manufacture of e.g. longitudinal beam of car, comprises providing a strip made of steel comprising iron and austenite, continuously coiling the strip and cooling, and then rolling

摘要

The method comprises providing a strip (2) made of steel comprising 60 wt.% iron and 5 vol.% of austenite content, continuously coiling the strip and then cooling to a temperature of >= 20[deg] C, and then rolling at a temperature of >= 20[deg] C. A final thickness of the strip is 0.5-1 mm. The method further comprises heat treating the strip before the cooling step and after the rolling step, and coating a surface of the strip, preferably zinc plating after the rolling step. The strip after the rolling has a tensile strength of 900 MPa and/or a yield strength of 600 MPa. The method comprises providing a strip (2) made of steel comprising 60 wt.% iron and 5 vol.% of austenite content, continuously coiling the strip and then cooling to a temperature of >= 20[deg] C, and then rolling at a temperature of >= 20[deg] C. A final thickness of the strip is 0.5-1 mm. The method further comprises heat treating the strip before the cooling step and after the rolling step, and coating a surface of the strip, preferably zinc plating after the rolling step. The strip after the rolling has a tensile strength of 900 MPa and/or a yield strength of 600 MPa. A degree of rolling in the rolling step is 30%. The degree of rolling over the width and/or length of the strip is different. The rolled strip or derived gap tape or sheets are further processed by a roll-forming or deep-drawing process. Independent claims are included for: (1) an apparatus for producing a rolled steel strip; and (2) a rolled steel strip.