A method for heat treatment of an object of sheet metal, includes the step of heating at least one selected portion of the object using an energy beam. The beam is projected onto a surface of the object so as to produce a primary spot on the object, the beam being repetitively scanned in two dimensions in accordance with a scanning pattern so as to establish an effective spot on the object, the effective spot having a two-dimensional energy distribution. The effective spot is displaced in relation to the surface of the object to progressively heat the at least one selected portion of the object. The scanning pattern includes interconnected curved segments.

A method to improve the formability of steel blanks, for steels containing at least 5% martensite, and possibly some ferrite, bainite and residual austenite and having an ultimate tensile strength of at least 500 MPa and possibly having a metallic coating layer on at least one side, wherein the steel blank is heat-treated on at least part of its peripheral thickness using at least one heat source, which heats the steel in a heat-treated zone to a temperature between 400° C. and 1500° C. without melting the steel in any points of the heat-treated zone.

The invention relates to a method for additive production of a component layer of a component including the steps of: generating at least one layer from a powdery component material in the region of a structuring and joining zone; subdividing model data of the layer into virtual sub-regions by a control device; selecting at least one of the virtual sub-regions by the control device; localized heating of at least one heating region in a real sub-region of the layer corresponding with the selected virtual sub-region by a heating device; verifying whether a temperature of the layer has, in a predetermined inspection region, a predetermined minimum temperature; and localized solidifying of the layer in a predetermined solidifying region by selective irradiation by at least one energy beam of an energy source, if the layer has the predetermined minimum temperature in the inspection region.

A method for manufacturing an object including the steps of forming layers by adding successive layers of material to form the object by selective laser melting (SLM), and inducing plastic deformation and residual stress into solidified material of at least one of the successive layers of material to improve mechanical properties and a fatigue resistance of the object, wherein the plastic deformation and the residual stress are induced by a laser.

The present invention provides a grain-oriented electrical steel sheet with reduced iron loss over a wide range of sheet thickness by providing a grain-oriented electrical steel sheet with an actually measured sheet thickness t (mm) that includes a closure domain region extending linearly in a direction from 60 to 120 with respect to the rolling direction on a surface of the steel sheet, the closure domain region being formed periodically at a spacing s (mm) in the rolling direction, such that h74.9t+39.1 (0.26t), h897t174.7 (t>0.26), (wh)/(s1000)12.6t+7.9 (t>0.22), and (wh)/(s1000)40.6t+14.1 (t0.22), where h (m) is the depth and w (m) is the width of the closure domain region.

The present invention provides a grain-oriented electrical steel sheet with reduced iron loss over a wide range of sheet thickness by providing a grain-oriented electrical steel sheet with an actually measured sheet thickness t (mm) that includes a closure domain region extending linearly in a direction from 60 to 120 with respect to the rolling direction on a surface of the steel sheet, the closure domain region being formed periodically at a spacing s (mm) in the rolling direction, such that h74.9t+39.1 (0.26t), h897t174.7 (t>0.26), (wh)/(s1000)12.6t+7.9 (t>0.22), and (wh)/(s1000)40.6t+14.1 (t0.22), where h (m) is the depth and w (m) is the width of the closure domain region.

A method for manufacturing a strip having a variable thickness along its length, comprising the steps: an initial strip of constant thickness is provided; homogeneous cold rolling of the initial strip along its length in order to obtain an intermediate strip of constant thickness along the rolling direction; flexible cold rolling of the intermediate strip along its length in order to obtain a variable thickness strip, having, along its length, first areas with a first thickness (e+s) and second areas with a second thickness (e), less than the first thickness (e+s), continuous annealing of the strip. The plastic deformation ratio generated, after an optional intermediate recrystallization annealing, by the homogeneous cold rolling and the flexible cold rolling steps in the first areas is greater than or equal to 30%.

A method for manufacturing a strip having a variable thickness along its length, comprising the steps: an initial strip of constant thickness is provided; homogeneous cold rolling of the initial strip along its length in order to obtain an intermediate strip of constant thickness along the rolling direction; flexible cold rolling of the intermediate strip along its length in order to obtain a variable thickness strip, having, along its length, first areas with a first thickness (e+s) and second areas with a second thickness (e), less than the first thickness (e+s), continuous annealing of the strip. The plastic deformation ratio generated, after an optional intermediate recrystallization annealing, by the homogeneous cold rolling and the flexible cold rolling steps in the first areas is greater than or equal to 30%.

The apparatus serves for inhomogeneous cooling of a flat object with a first main face and a second main face opposite the first main face. The flat object is cooled by a cooling device from the direction of the first main face. On the second main face, a heating device locally acts upon a first partial face in such a way that the flat object is subjected to heat at said first partial face relative to a second partial face adjoining said first partial face in such a way that said first partial face is cooled more slowly in comparison with the second partial face and, during the cooling process, the second main face of the flat object therefore has an inhomogeneous temperature distribution at least in a partial time period of the cooling.

A grain-oriented electrical steel sheet, on which magnetic domain refining treatment by strain application has been performed, has an insulating coating with excellent insulation properties and corrosion resistance. In a grain-oriented electrical steel sheet, linear strain having been applied thereto by irradiation with a high-energy beam, the linear strain extending in a direction that intersects a rolling direction of the steel sheet, an area ratio of irradiation marks within an irradiation region of the high-energy beam is 2% or more and 20% or less, an area ratio of protrusions with a diameter of 1.5 m or more within a surrounding portion of the irradiation mark is 60% or less, and an area ratio of exposed portions of steel substrate in the irradiation mark is 90% or less.