Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 MgZn2 layer forms in the coating above the Al layer.

Abstract: A flat steel product, comprising a base layer consisting of a steel material, and a multilayer coating applied thereto, and a method for producing the flat steel product.

Abstract: A flat steel product provided with a coating system, which in the coated state possesses an optimized combination of corrosion resistance and welding capacity, includes a base layer formed from a steel and a corrosion protection system applied onto the base layer. The corrosion protection system comprises a metallic coating less than 3.5 ?m thick, formed from a first metallic layer applied onto the base layer and a second metallic layer applied onto the first metallic layer, wherein the second metallic layer has formed a metallic alloy with the first metallic layer. The corrosion protection system also comprises a plasma polymer layer applied onto the metallic coating.

Abstract: 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.

Abstract: A flat steel product provided with a coating system, which in the coated state possesses an optimized combination of corrosion resistance and welding capacity, includes a base layer formed from a steel and a corrosion protection system applied onto the base layer. The corrosion protection system comprises a metallic coating less than 3.5 ?m thick, formed from a first metallic layer applied onto the base layer and a second metallic layer applied onto the first metallic layer, wherein the second metallic layer has formed a metallic alloy with the first metallic layer. The corrosion protection system also comprises a plasma polymer layer applied onto the metallic coating.

Abstract: A cost-favorable process for production of corrosion-resistant sheet steel products, having good characteristics of use for certain application purposes includes applying a zinc-containing coating by electro-galvanizing a flat steel product, finally cleaning mechanically and/or chemically the flat steel product, applying a magnesium-based coating to the finally cleaned zinc-containing coating by means of vapour deposition, and heat treating the coated flat steel product to form a diffusion or convention layer between the zinc-containing coating and the magnesium-based coating at a temperature of 320 ° C. to 335 ° C. under normal atmosphere.