Voestalpine Stahl Gmbh

Alois Leitner

Reinhard Hackl

Christoph Etzlstorfer

Karl-Heinz Stellnberger

Christian Schmaranzer

Roland Rechberger

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:&#x3bc;&#x3e;&#x3bc;,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.

Method for producing steel composite materials

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.

Three-layered composite in the form of a metal sheet or strip, component having such a composite, and the use thereof

A girder is described for a vehicle chassis made of at least two sheet metal profiles () composed along their longitudinal edges into a circumferentially enclosed hollow profile (), which hollow profile comprises at least two longitudinal sections () which are both materially joined by way of a joining seam (). In order to provide advantageous constructional conditions it is proposed that one of the two longitudinal sections () consists of an iron material and the other longitudinal section () of the hollow profile () consists of an aluminum material, and that the joining seam () forming a welded/soldered connection between the butt-jointed longitudinal sections () of the hollow profile () comprises an additional material () on the basis of aluminum as solder which is applied into a coating of the iron material in a width (b) corresponding to at least three times the thickness (d) of said iron material

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Weyregg am Attersee, Austria

Alois Leitner