Method of producing cold rolled steel strip

Abstract

Method of producing strip comprising continuously casting plain carbon steel into a strip of no more than 5 mm thickness and coiling the strip. The strip is subsequently uncoiled and cold rolled then annealed to produce a stress relieved microstructure therein. The cold rolling produces a cold reduction sufficient to increase the tensile strength of the strip to at least 680 MPa but is such that the total elongation to break off the strip after the annealing is in the range 8% to 12%. The cold rolling may produce a cold reduction of the strip thickness in the range 40% to 80%. The continuously cast strip may be optionally in-line hot rolled prior to coiling to produce an initial strip thickness in the range 40% to 60%.

Dependencies are inferred from the claim text.