Abstract: The invention relates to a method for producing a steel composite in which at least two steel sheets that consist of different steel grades are placed against each other, hot rolled together, and then possibly cold rolled and in which after the rolling, the composite material, which is thus produced from at least two layers with different steel compositions, is diffusion annealed, wherein the annealing temperature is set so as to select the chemical potential of the steel materials to correspond to the following equation: ?C,material 1>?C,material 2, where material 1 has a lower carbon content than material 2 so that an uphill diffusion of carbon takes place between material 1 and material 2.

Abstract: A three-layered composite has the form of a metal sheet or strip. A first core layer having a first steel material forms a composite central layer. A second plating layer has a second steel material different from the first steel material. A third plating layer has a third steel material different from the first steel material. The second and third plating layers are roll-plated onto opposite sides of the core layer and form the outer two composite layers. While the composite thickness remains the same, the first steel material thickness varies over the width of the composite. The first steel material extends, and can be press-hardened, continuously over the entire width of the composite material. The second and/or third steel materials, in the plating-layer thickness, follow the variation of the core-layer thickness in opposite directions and have a carbon content lower than that of the first steel material.

Abstract: The invention relates to a method for producing a steel composite in which at least two steel sheets that consist of different steel grades are placed against each other, hot rolled together, and then possibly cold rolled and in which after the rolling, the composite material, which is thus produced from at least two layers with different steel compositions, is diffusion annealed, wherein the annealing temperature is set so as to select the chemical potential of the steel materials to correspond to the following equation: ?C, material 1>?C, material 2, where material 1 has a lower carbon content than material 2 so that an uphill diffusion of carbon takes place between material 1 and material 2.

Abstract: A three-layered composite has the form of a metal sheet or strip. A first core layer having a first steel material forms a composite central layer. A second plating layer has a second steel material different from the first steel material. A third plating layer has a third steel material different from the first steel material. The second and third plating layers are roll-plated onto opposite sides of the core layer and form the outer two composite layers. While the composite thickness remains the same, the first steel material thickness varies over the width of the composite. The first steel material extends, and can be press-hardened, continuously over the entire width of the composite material. The second and/or third steel materials, in the plating-layer thickness, follow the variation of the core-layer thickness in opposite directions and have a carbon content lower than that of the first steel material.