Abstract: A method for producing a steel strip with a multiphase structure by which the production of complex geometries with a high energy-absorption capacity and high resistance to edge cracking is provided achieving a high yield strength or high yield-strength ratio and a high elongation at break, comprising producing a rolled steel strip of particular elements, and first annealing the steel strip at a temperature of between 750° C. and 950° C., and subsequently first cooling of the steel strip to a temperature of between 200° C. and 500° C. at an average cooling rate of 2 K/s to 150 K/s, further cooling of the steel strip to a supercooling temperature below 100° C. at an average cooling rate of 1 K/s to 50 K/s, final annealing of the steel strip with a Hollomon-Jaffe parameter, and final cooling of the steel strip to room temperature at an average cooling rate of 1 K/s to 160 K/s.

Abstract: A steel strip made of a high-strength multiphase steel with a tensile strength of at least 780 MPa in the longitudinal direction and consists of the following elements in % by weight: 0.08?C?0.23, 1.5?Mn?3.5, 0.25?Si+Al?2, 0.0020?N?0.0160, P<0.05, S<0.01. Cu<0.20; iron; and a carbon equivalent CEV which is greater than 0.49 and smaller than 0.9, wherein the carbon equivalent CEV results from the contents of the corresponding elements in % by weight according to the following formula: CEV=C+Mn/6 (Cu+Ni)/15+(Cr+Mo+V)/5 and wherein the ratio of the carbon equivalent CEV and the sum of the contents of Si and Al in % by weight is less than 2.3, wherein the multiphase steel constituents martensite, tempered martensite, residual austenite, upper bainite and/or lower bainite where the sum of the volume fractions of the microstructure is at least 30% by volume, and residual microstructure consists of ferrite and perlite.

Abstract: A method for producing a steel strip with a multiphase structure by which the production of complex geometries with a high energy-absorption capacity and high resistance to edge cracking is provided achieving a high yield strength or high yield-strength ratio and a high elongation at break, comprising producing a rolled steel strip of particular elements, and first annealing the steel strip at a temperature of between 750° C. and 950° C., and subsequently first cooling of the steel strip to a temperature of between 200° C. and 500° C. at an average cooling rate of 2 K/s to 150 K/s, further cooling of the steel strip to a supercooling temperature below 100° C. at an average cooling rate of 1 K/s to 50 K/s, final annealing of the steel strip with a Hollomon-Jaffe parameter, and final cooling of the steel strip to room temperature at an average cooling rate of 1 K/s to 160 K/s.