Thyssenkrupp Steel Europe Ag

Thyssen Krupp Ag

Nicole Weiher

Bernd Schuhmacher

Michael Steinhorst

Jens-Ulrik Becker

Stefan Wischmann

Fabian Junge

Roland Wunderlich

Horst Walter Tamler

Christian Schwerdt

Frank Panter

Stefan Peter Puls

Gregor Müller

Richard Weinhold

Krasimir Nikolov

Heinrich Meyring

A method of activating a metal surface, such as a galvanized steel sheet, before a phosphating process, may involve bringing the metal surface into contact with an activating bath containing activating particles, which may be based on phosphate and/or titanium, dispersed in water. To alleviate or even eliminate the problems of poor adhesion of surface coatings to preferably electrolytically galvanized, phosphated metal strip, an additive that suppresses or at least slows agglomeration of the activating particles may be added to the activating bath. In some examples, polyethylene glycol (PEG) and/or sodium stearate may be added. Further, the particle size distribution of the activating particles present in the activating bath may be determined and the activating bath may be replaced or taken out of operation as a function of the particle size distribution of the activating particles.

Method for activating metal surfaces to be phosphated

A bipolar plate which can be produced particularly economically for a fuel cell, with which a high degree of efficiency is guaranteed over a long service life. The bipolar plate has a core layer consisting of a steel material, the surfaces of said core layer, which are associated with the respective electrolyte carriers of the fuel cell, having a corrosion protection layer, protecting the core layer against corrosion. The corrosion protection layers consist of a metal material and extend on both sides over the whole surface of the core layer. At the same time the corrosion protection layers are in turn coated over the whole surface with an electrically conductive functional coating, which is essentially entirely impermeable for the metal ions emerging from the core layer and/or the corrosion protection layers. The invention likewise relates to at least one fuel cell comprising a bipolar plate according to the invention.

Bipolar plate for a fuel cell and fuel cell stack

A flat steel product having a base layer of a steel material and a multilayer coating applied thereto, and a method for producing the flat steel product. The method having the following steps: providing a steel base layer; applying a zinc layer to the base layer by electrolytic coating; applying an aluminum layer to the surface of the zinc layer, wherein no treatment is made to the surface of the zinc layer in regard to the oxides and sulfides present thereon at the end of the electrolytic zinc coating step or occurring during the course of the aluminum coating step; applying a magnesium layer to the aluminum layer; and subsequently heat treating the flat steel product in such a way that an MgZnlayer forms in the coating above the Al layer.

Method for the production of a flat steel product and flat steel product

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Bochum, Germany

Nicole Weiher