Abstract: A method for producing a steel component provided with a metallic coating which protects against corrosion, comprising the following steps: coating a steel flat product, produced from a low-alloy heat-treated steel, with an Al coating which contains at least 85% wt. Al and optionally up to 15% wt. Si; coating the steel flat product provided with the Al coating with a Zn coating which contains at least 90% wt. Zn; heating the steel flat product to a hot-forming temperature which is at least 750° C.; hot forming the heated steel component made from the steel flat product; and cooling the hot-formed steel component sufficiently quickly to form a tempered or martensitic structure.

Abstract: A method for coating hot-rolled or cold-rolled steel strip containing 6-30 wt %. Mn with a metallic protective layer, includes annealing the steel strip at a temperature of 800-1100° C. under an annealing atmosphere containing nitrogen, water and hydrogen and then subjecting the steel strip to hot dip coating. The method provide an economical way of hot dip coating a high manganiferous sheet steel in that, in order to produce a metallic protective layer substantially free from oxidic sub-layers on the steel strip, the % H2O/% H2 ratio of the water content % H2O to the hydrogen content % H2 in the annealing atmosphere is adjusted as a function of the respective annealing temperature TG as follows: % H2O/% H2?8·105·TG3.529.

Abstract: Economic production of highly corrosion-resistant flat steel products with a corrosion protection system, which are at the same time easy to process further, is described. The following work steps are applied: preheating the steel substrate to a strip temperature under inert gas atmosphere; cooling the steel substrate to the strip inlet temperature; hot dip coating of the steel substrate in a zinc bath so that a metallic corrosion protection coating is formed on the steel substrate which has an Al content of max 0.5 wt. % in an intermediate layer; adjusting the thickness of the metallic corrosion protection coating applied to the steel substrate in the melt bath to values of 3 to 20 ?m per side by scraping away excess coating material; cooling the steel substrate with the metallic corrosion protection coating; and applying the organic coating to the metallic corrosion protection coating of the steel substrate.

Abstract: A flat steel product, and a method for its production, which is formed from a steel substrate, such as strip or sheet steel, and a zinc-based corrosion protection coating, applied to at least one side of the steel substrate, which contains (in wt. %) Mg: 0.25 to 2.5%, Al: 0.2 to 3.0%, Fe: ?4.0%, and optionally in total up to 0.8% of one or more elements of the group Pb, Bi, Cd, Ti, B, Si, Cu, Ni, Co, Cr, Mn, Sn and rare earths, remainder zinc and unavoidable impurities are described. The corrosion protection coating has an Al content of maximum 0.5 wt. % in an intermediate layer extending between a surface layer directly adjacent to the surface of the flat steel product and a border layer adjacent to the steel substrate and with a thickness amounting to at least 20% of the total thickness of the corrosion protection coating.

Abstract: A method for coating a flat steel product manufactured from a high strength steel with a metallic coating, wherein the flat steel product is initially subjected to a heat treatment, in order then, in the heated state, to be hot-dip galvanized with the metallic coating in a melting bath containing overall at least 85% zinc and/or aluminum. The heat treatment includes heating the steel product in a reducing atmosphere, followed by converting a surface of the flat product to an iron oxide layer by a heat treatment lasting 1 to 10 secs in an oxidizing atmosphere, followed by annealing in a reducing atmosphere over a period of time which is longer than the duration of the formation of the iron oxide layer such that the iron oxide layer is reduced at least on its surface to pure iron, followed by cooling the product to a melting bath temperature.

Abstract: A process for melt dip coating a strip of high-tensile steel with alloy constituents including zinc and/or aluminum includes the following steps. The strip is heated in a continuous furnace initially in a reductive atmosphere to a temperature of approximately 650° C., at which the alloy constituents diffuse to the surface in small amounts. The surface, consisting predominantly of pure iron, is converted into an iron oxide layer by a short heat treatment at a temperature of up to 750° C. in a reaction chamber which is integrated in a continuous furnace and has an oxidizing atmosphere. In a subsequent annealing treatment at a higher temperature in a reductive atmosphere, this iron oxide layer prevents the alloy constituents from diffusing to the surface. In the reductive atmosphere, the iron oxide layer is converted into a pure iron layer to which the zinc and/or aluminium are applied in the molten bath with optimum adhesion.

Abstract: Coating steel strips comprising, in % by weight, C: ?1.6%, Mn: 6-30%, Al: ?10%, Ni: ?10%, Cr: ?10%, Si: ?8%, Cu: ?3%, Nb: ?0.6%, Ti: ?0.3%, V: ?0.3%, P: ?0.1%, B: ?0.01%, the rest being iron and unavoidable impurities, and a method of forming steel strips are described. Up to now, such steel strips were not adequately coatable, with a metal coating ensuring outstanding corrosion-resistance and good welding properties. This is ensured by applying an aluminium layer to the steel strip before final annealing and applying the metal coating to said aluminium layer after final annealing.

Abstract: The invention relates to a coated steel sheet or strip with a ground coating made of steel, onto at least one upper side of which a coating is applied by hot-dip galvanizing, the coating being formed from a melt consisting of 0.05-0.30% by weight Al and 0.2-2.0% by weight Mg, the remainder being zinc and unavoidable impurities, and, with a coating thickness of a maximum of 3.5 ?m on each side and a coating weight of a maximum 25 g/m2 on each side, guarantees that the steel sheet, in the salt spray mist test carried out in accordance with DIN 50021-SS, shows the first formation of red rust at the earliest after 250 hours. With such a sheet or strip, a flat steel product is provided which possesses an optimum combination of high corrosion resistance and optimum weldability and which is particularly well-suited for use as a material for motor vehicle chassis construction or for the construction of domestic appliances.

Abstract: The present invention relates to a method for the manufacture of galvannealed metal sheet, wherein a hot strip is produced from an IF steel containing 0.01 to 0.1 wt. % silicon, wherein the hot strip is coiled at a coiler temperature no lower than 700° C. and no higher than 750° C., wherein a cold strip is rolled from the coiled hot strip, wherein the cold strip is recrystallization-annealed in an annealing furnace in an annealing gas atmosphere, wherein the cold strip thus annealed is provided with a zinc coating in a zinc bath, and wherein the coated cold strip is post-annealed at a galvannealing temperature no lower than 500° C. and no higher than 540° C. The invention also relates to a galvannealed metal sheet which possesses improved adhesion of the coating layer to the base material and proposes a method which is suited for the manufacture of metal sheet having such properties.

Abstract: The present invention relates to a method for the manufacture of galvannealed metal sheet, wherein a hot strip is produced from an IF steel containing 0.01 to 0.1 wt. % silicon, wherein the hot strip is coiled at a coiler temperature no lower than 700° C. and no higher than 750° C., wherein a cold strip is rolled from the coiled hot strip, wherein the cold strip is recrystallisation-annealed in an annealing furnace in an annealing gas atmosphere, wherein the cold strip thus annealed is provided with a zinc coating in a zinc bath, and wherein the coated cold strip is post-annealed at a galvannealing temperature no lower than 500° C. and no higher than 540° C. The invention also relates to a galvannealed metal sheet which possesses improved adhesion of the coating layer to the base material and proposes a method which is suited for the manufacture of metal sheet having such properties.