A method for heating a blank or a preformed steel sheet component for hot forming and/or quench hardening purposes. In at least some regions, the heating is carried out to a temperature above AC3; the heating of the Hank is embodied as a rapid heating and to this end, the blank is heated in a first zone at an average heating rate of >25 K/s up to about 600° C. and above this temperature, is heated at an average heating rate of >10 K/s up to a maximum of the AC3 temperature and then is transferred to a second zone in which the blank that has been preheated in the first zone is heated in at least some regions to temperatures greater than AC3, in particular >850° C., with the heating rate in the second zone being >10 K/s. The invention also relates to a device for carrying out the method.

The present invention relates to a hot stamped component, a precoated steel sheet used for hot stamping, and a hot stamping process. The hot stamped component of the present invention is provided with a coating of aluminium or an aluminium alloy on at least one surface of the base steel, the coating is produced by interdiffusion between the base steel and a precoating of aluminium or aluminium alloy, and the coating has a thickness of 6 to 26 μm.

The present invention relates to a hot stamped component, a precoated steel sheet used for hot stamping, and a hot stamping process. The hot stamped component of the present invention is provided with a coating of aluminium or an aluminium alloy on at least one surface of the base steel, the coating is produced by interdiffusion between the base steel and a precoating of aluminium or aluminium alloy, and the coating has a thickness of 6 to 26 μm.

Methods for processing bonded dual alloy rotors are provided. In one embodiment, the method includes obtaining a bonded dual alloy rotor including rotor blades bonded to a hub disk. The rotor blades and hub disk are composed of different alloys. A minimum processing temperature (T.sub.DISK.sub._.sub.PROCESS.sub._.sub.MIN) for the hub disk and a maximum critical temperature for the rotor blades (T.sub.BLADE.sub._.sub.MAX) is established such that T.sub.BLADE.sub._.sub.MAX is less than T.sub.DISK.sub._.sub.PROCESS.sub._.sub.MIN. A differential heat treatment process is then performed during which the hub disk is heated to processing temperatures equal to or greater than T.sub.DISK.sub._.sub.PROCESS.sub._.sub.MIN, while at least a volumetric majority of each of the rotor blades is maintained at temperatures below T.sub.BLADE.sub._.sub.MAX. Such a targeted differential heat treatment process enables desired metallurgical properties (e.g., precipitate hardening) to be created within the hub disk, while preserving the high temperature properties of the rotor blades and any blade coating present thereon.

A method of recovery heat treatment of a workpiece includes contacting at least a portion of the workpiece with a fluid heated to a temperature sufficient to heat the at least a portion of the workpiece to a predetermined temperature range in a predetermined time period. The method may be implemented as a first step of a two-stage recovery heat treatment or annealing process, followed by a second step of heating the at least a portion of the workpiece to a final target temperature by another annealing process.

A method of recovery heat treatment of a workpiece includes contacting at least a portion of the workpiece with a fluid heated to a temperature sufficient to heat the at least a portion of the workpiece to a predetermined temperature range in a predetermined time period. The method may be implemented as a first step of a two-stage recovery heat treatment or annealing process, followed by a second step of heating the at least a portion of the workpiece to a final target temperature by another annealing process.

A method for manufacturing a friction plate provided with a core plate includes subjecting a spline portion formed at an outer periphery or an inner periphery of the core plate to a hardening process by laser.

A method for manufacturing a friction plate provided with a core plate includes subjecting a spline portion formed at an outer periphery or an inner periphery of the core plate to a hardening process by laser.

A cold-rolled sheet is provided. The cold-rolled sheet includes a steel substrate with a carbon content C.sub.0 between 0.07% and 0.5%, expressed by weight, and a metal pre-coating on at least the two principal faces of the steel substrate. The substrate has a decarburized area on the surface of each of the two principal faces. The depth p.sub.50% of the decarburized area is between 6 and 30 micrometers, and p.sub.50% is the depth at which the carbon content is equal to 50% of the content C.sub.0. The sheet does not contain a layer of iron oxide between the substrate and the metal pre-coating.

Disclosed is a grain-oriented electrical steel sheet that exhibits excellent iron loss properties and a good building factor, in which damage to a tension coating is suppressed. In a grain-oriented electrical steel sheet having a tension coating, an interlaminar current is 0.15 A or less, a plurality of linear strain regions extending in a direction transverse to the rolling direction are formed, the strain regions are formed at line intervals in the rolling direction of 15 mm or less, each of the strain regions has closure domains formed therein, and each of the closure domains has a length d along the sheet thickness direction of 65 μm or more and a length w along the rolling direction of 250 μm or less.