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 method for coating a hot-rolled or cold-rolled steel flat product, containing 6-30% wt. Mn, with a metallic protective layer by hot-clip coating in a melt bath. The coating, achieved with increased production reliability, is optimised by the steel flat product being subjected to a pickling treatment in which the manganese oxide adhering to the steel flat product is essentially fully removed in the pickling bath before the steel flat product enters the melt bath.

Abstract: A multilayered composite part includes a plurality of steel alloy layers connected to one another, with at least one core layer consisting of a soft, well deformable steel alloy and at least one steel alloy layer of a very high strength steel alloy, arranged on the core layer. A multilayered composite part which is characterized simultaneously by a high strength paired with very good outer skin quality and very good paint adherence, is achieved in that at least one outer steel alloy layer of a soft, well deformable steel alloy is provided on the very high strength steel alloy layer.

Abstract: A method for producing a steel component provided with a metallic coating which protects against corrosion, in which a steel flat product, produced from an alloyed heat-treated steel, is coated with an Al coating which contains ?85% wt. Al and optionally ?15% wt. Si, a Zn coating with ?90% wt. Zn, and a top layer, the main constituent of which is at least one metal salt of phosphoric acid or diphosphoric acid and which additionally can contain contents of up to 45% of an Al:Zn ratio as well as optionally metal oxides, metal hydroxides and/or sulphur compounds, the steel flat product is heat treated at ?750° C., and the steel component is hot-formed from the heated steel flat product. The hot-formed steel component is cooled at a cooling rate sufficient to form a tempered or martensitic structure.

Abstract: A method for coating a hot-rolled or cold-rolled steel flat product, containing 6-30% wt. Mn, with a metallic protective layer by hot-clip coating in a melt bath. The coating, achieved with increased production reliability, is optimised by the steel flat product being subjected to a pickling treatment in which the manganese oxide adhering to the steel flat product is essentially fully removed in the pickling bath before the steel flat product enters the melt bath.

Abstract: A steel flat product having a Zn—Mg—Al coating. The coating, which in addition to zinc and unavoidable impurities, comprises in wt. %: Mg: 4-8%, Al: 0.5-1.8% and optionally one or more of the following: Si: <2%, Pb: <0.1%, Ti: <0.2%, Ni: <1%, Cu: <1%, Co: <0.3%, Mn: <0.5%, Cr: <0.2%, Sr: <0.5%, Fe: <3%, B: <0.1%, Bi: <0.1%, Cd: <0.1%, REM<0.2%, and Sn<0.5%. The steel flat product according to the invention is not only outstandingly protected against corrosion, but also welds well and coats well with an organic layer applied subsequently. The invention also relates to a method for producing a steel flat product having a Zn—Mg—Al coating.

Abstract: A multilayered composite part includes a plurality of steel alloy layers connected to one another, with at least one core layer consisting of a soft, well deformable steel alloy and at least one steel alloy layer of a very high strength steel alloy, arranged on the core layer. A multilayered composite part which is characterized simultaneously by a high strength paired with very good outer skin quality and very good paint adherence, is achieved in that at least one outer steel alloy layer of a soft, well deformable steel alloy is provided on the very high strength steel alloy layer.

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 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.

Abstract: Device for the alumino-thermic welding of two ends of a rail A device for the alumino-thermic welding of two ends of a rail, namely a casting mould (4) which is open on the upperside and which comprises a central casting chamber which is defined by the rail ends, which are spaced apart from each other by a welding groove (3), and also by the walls of the casting mould (4) and to the side of the casting chamber said casting mould comprises at least one riser (13) which is permeably connected to the casting chamber only in the region of the rail foot (11), and wherein a reaction pot (1) is provided on the base side with an outflow device which causes a steel melt to flow out of the reaction pot (1) and into the casting mould (4), is configured substantially to obviate turbulent flow conditions inside the casting mould and to homogenise the solidification of an intermediate cast structure between the ends of the rail such that the steel issuing out of the reaction pot (1) after the completion of an alumino-therm

Abstract: The invention relates to a process for the aluminothermic welding of rails, the aluminothermically produced steel being poured into a refractory mold surrounding the rail ends which are to be joined, and alloying additives being contacted with that part of the steel which runs out of the reaction crucible and forms the weld in the rail head region, wherein the alloying with the alloying additives is carried out after the completion of the aluminothermic reaction and separation of the steel from the slag via the diverting plug in the mold, and the overflow in the is closed.

Abstract: The invention relates to a process for the aluminothermic welding of rails, the aluminothermically produced steel being poured into a refractory mold surrounding the rail ends which are to be joined, and alloying additives being contacted with that part of the steel which runs out of the reaction crucible and forms the weld in the rail head region, wherein the alloying with the alloying additives is carried out after the completion of the aluminothermic reaction and separation of the steel from the slag during tapping and before the steel runs into the casting cavity formed by the mold, and the overflow in the casting mold is closed.

Abstract: The invention relates to an automatically opening tapping thimble made from a refractory material for casting crucibles which are used in aluminothermic reactions. This thimble consists entirely or partially of air-permeable graphite or metal whose melting point lies between 2100 and 3727.degree. C.

Abstract: The invention relates to an aluminothermic mixture consisting of a finely particulate base portion of iron oxides and aluminum as well as metallic additives, wherein a master alloy, namely a ferrochromium alloy consisting of (in % by weight)C: 0.1 to 20Si: 2 to 40Cr: 5 to 80and iron with impurities resulting from manufacture and, if appropriate, other alloying elements, is added in a quantity of from 5 to 50% by weight, relative to the base portion, as metallic additive.

Abstract: In order to reduce the residual stresses which occur in the region of a fusion weld of two rail ends (1,2), in order to reduce, in particular to make uniform, the cooling-down rate and--associated with this--the crystallization process within the solidifying weld material, a casting mold is proposed which is equipped with a system of risers (9) and air vents (10) which are designed symmetrically with respect to a longitudinal center plane (5) and a transverse center plane (3) of the welded joint, the risers (9) and the air vents (10) being physically distributed as a function of geometric parameters of the rail foot (8) and of the weld bead (4), and the cross sections of the air vents (10) being dimensioned as a function of the cross sections of the risers (9).

Abstract: Disclosed is a method for the aluminothermal production of molten steel for the aluminothermal welding of workpieces, wherein the aluminothermal reaction is carried out in a crucible made of porous or hollow spherical .alpha.-Al.sub.2 O.sub.3 with a density of 0.8-3.0 g/cm.sup.3 and a bulk density of 0.3-1.8 g/cm.sup.3.

Abstract: The invention relates to a plain bearing alloy on a tin basis with antimony and copper, the alloy consisting of 6 to 15% by weight of antimony, 3 to 10% by weight of copper, 0.05 to 1% by weight of silver and 0.1 to 2% by weight of zinc, the remainder being tin.

Abstract: A method for the preparation of alloys of the SE.sub.2 Fe.sub.17-x TM.sub.xN.sub.y type where SE stands for a rare earth metal, including Y or a mixture of these metals, while TM stands for Co, Ni, Cu, Zr, Ga, Hf, Ta, Nb, Ti, Si, A1, V, Mo, Cr, Zn or Sn or a mixture of these metals, x=0 to 10, y=>0 to 5 is described. The preparation involves calciothermal reduction of a finely divided, homogeneous mixture of the alloying components, subsequent diffusion of the components, followed by nitriding and separating the calcium oxide and excess calcium formed. The method is characterized by:a) Preparation of an alloy of the SE.sub.2 Fe.sub.17-x TM.sub.x bya1) Adjusting the exothermic reaction of the calciothermal reduction by the oxide content of the reaction mixture, so that T.sub.M >TR .gtoreq.0.9 T.sub.M where T.sub.M is the melting temperature of the intermetallic phase, and T.sub.

Abstract: A method for producing single-phase intermetallic phases, which melt incongruently within a temperature range of 900.degree. to 2,000.degree. K., with a homogeneity range of .ltoreq.10 atom % at room temperature by co-reduction is described. The exothermic reaction of the calciothermal reduction is adjusted by altering the oxide content of the reaction mixture, the composition of which corresponds to the desired single-phase alloy, in such a way that the temperature condition T.sub.m >T.sub.R .gtoreq.0.9 T.sub.m (in .degree. K.) is fulfilled, T.sub.m being the melting temperature of the intermetallic phase and T.sub.R the reaction temperature. The components of the reaction mixture, with the exception of calcium, have an average particle size of .ltoreq.75 .mu.m. The reaction product at the end of the exothermic reaction is tempered at a temperature which is at least 0.7 times the melting temperature T.sub.m of the desired, single-phase alloy, measured in .degree. K.