A method for manufacturing a sheet metal component including: annealing a flat steel product comprising 0.05-0.5% C, 0.5-3% Mn, 0.06-1.7% Si, ≤0.06% P, ≤0.01% S, ≤1.0% Al, ≤0.15% Ti, ≤0.6% Nb, ≤0.01% B, ≤1.0% Cr, ≤1.0% Mo, ≤1.0% Cr+Mo, ≤0.2% Ca, ≤0.1% V, remainder iron and impurities in a continuous furnace under an atmosphere consisting of 0.1-15% hydrogen and remainder nitrogen with a specific dew point and temperature profile; applying a coating consisting of ≤15% Si, ≤5% Fe, in total 0.1-5% of at least one alkaline earth or transition metal and a remainder Al and unavoidable impurities; heating the fat steel product to >Ac3 and ≤1000° C. for a time sufficient to introduce a heat energy quantity>100,000-800,000 kJs; hot-forming the flat steel product to form the component; and cooling at least one section of the component at a cooling rate sufficient to generate hardening structures.

A method and arrangement for manufacturing hot dip galvanized rolled high strength steel product is presented. The method comprises providing a rolled steel product, heating and annealing the rolled steel product for creating a layer of iron oxide on the surface of the rolled steel product, cooling the rolled steel product, having the iron oxide layer, in a first cooling step to a temperature in a temperature range of 560-600° C. and holding for 3-10 seconds, quenching said rolled steel product, covered with the layer of iron oxide, in a second cooling step by immersing it into a zinc bath comprising aluminium and having a temperature between 440-450° C. for 1-5 seconds and cooling the rolled steel product in a third cooling step to room temperature. An arrangement for implementing the method is also presented.

A furnace for annealing a sheet includes: a first section; a second vertical section, the second vertical section including openings supplied with an oxidizing medium, an opening facing each side of the sheet, and means for separately controlling a flow of the oxidizing medium on each side of the sheet; and a third section. The second vertical section is located in a distinct casing and separated from the first and third sections with sealing devices. The second vertical section includes extraction openings for extracting the oxidizing medium not consumed by the sheet, an extraction opening facing each side of the sheet. The openings supplied with an oxidizing medium are located transversally at one end of the second vertical section. The extraction openings are located transversally at an other end of the second vertical section.

A method for heat-treating a metal strip, where the metal strip is pre-heated continuously in a pre-heating zone with the aid of hot gas and subsequently undergoes further heat treatment in a directly fired furnace in a reducing and/or oxidizing atmosphere. The metal strip is pre-heated in the pre-heating zone with hot inert gas and further heated with an electric heating system before entering the directly fired furnace. A furnace plant for implementing the process and a related heat recovery system are also disclosed.

A method for controlling surface reactions on a steel strip running through a furnace includes, successively, a first section, a second section, and a third section separated by a sealing element, an atmosphere in the second and third sections being oxidizing and reducing respectively, the method including: heating, in the first section, the steel strip to between 600 and 750° C., while causing the atmosphere therein to be slightly oxidizing and to include: an H.sub.2 content inferior to 2%; an O.sub.2 content inferior to 0.1%; an H.sub.2O or CO.sub.2, or H.sub.2O+CO.sub.2 content superior to 0.03%; a controlled dew point ranging from −50 to −15° C.; and a controlled concentration of CO+CO.sub.2 maintained below 2%. All percentages are expressed in terms of volume.

Provided is a continuous annealing line capable of producing a steel sheet excellent in hydrogen embrittlement resistance. A continuous annealing line 100 comprises: a payoff reel 10 configured to uncoil a cold-rolled coil C to feed a cold-rolled steel sheet S; an annealing furnace 20 configured to continuously anneal the cold-rolled steel sheet S and including a heating zone 22, a soaking zone 24, and a cooling zone 26 that are arranged from an upstream side in a sheet passing direction; a downstream line 30 configured to continuously pass the cold-rolled steel sheet S discharged from the annealing furnace 20 therethrough; a tension reel 50 configured to coil the cold-rolled steel sheet S; and a sound wave irradiator 60 configured to irradiate the cold-rolled steel sheet S being passed from the cooling zone 26 to the tension reel 50 with sound waves.

The present invention relates to a manufacturing method of a steel strip, a steel strip with controlled decarburized depth, a spot welded joint and the use of said steel strip or said spot welded joint. This invention is particularly well suited for the automotive industry due to the improvement of the Liquid Metal Embrittlement (LME) resistance along with target mechanical properties.

A method for producing a hot-dip galvanized steel sheet includes supplying humidified gas to the soaking zone 12 in a manner such that: in passes in which the steel sheet moves upward, the humidified gas is supplied from first humidified gas supply ports 40A to 40E provided at positions higher by 1.0 m or more and 5.0 m or less than the centers of lower hearth rolls 54 and overlapping the steel sheet in the passes when viewed from the side of the soaking zone; and in passes in which the steel sheet moves downward, the humidified gas is supplied from second humidified gas supply ports 42A to 42E provided at positions lower by 1.0 m or more and 5.0 m or less than the centers of the upper hearth rolls 52 and overlapping the steel sheet in the passes when viewed from the side of the soaking zone.

A device and method for producing a continuous strip-shaped composite material including a base material of metal, which is unwound in the form of a metal strip by a first coil-unwinding apparatus, and at least one cladding material of metal, which is unwound in the form of a metal strip by a second coil-unwinding apparatus. The metal base and cladding metal strips unwound by the respective coil-unwinding apparatuses are brought together in the hot state of at least 720 degrees Celsius. The unwound base and cladding metal strips brought toward each other and are joined by hot-rolling such that a single continuous strip-shaped composite material is thereby formed by roll cladding such that the composite material includes the base material and the cladding material.

A method for operating an annealing furnace to anneal a metal strip provides that, initially, at least one target material property (MP.sub.Target) is specified for a point or a section of the metal strip after passing through the annealing furnace. In addition, information (E) on the metal strip is provided before or in the annealing furnace. A calculation of a target temperature distribution (T.sub.Target) and/or a target speed (V.sub.Target) of the metal strip in the annealing furnace is then carried out with the assistance of a computer-aided model as a function of the target material properties and the specified information. The target temperature distribution and/or target speed calculated in this manner is/are subsequently set in the annealing furnace in order to transfer the material property of the metal strip behind the annealing furnace to the desired target material property MP.sub.Target.