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.

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 non-oriented electrical steel strip or sheet having the following composition, in percent by weight: 3.2 to 3.4 of Si, 0.85 to 1.1 of Al, 0.07 to 0.18 of Mn, 0.01 to 0.04 of P, 0.0003 to 0.0030 of S, 0.0005 to 0.0020 of N, 0.0010 to 0.0050 of C, 0.0015 to 0.0040 of Ti, 0.01 to 0.008 of Cr, up to 0.05 in total of Nb+Mo+V, balance Fe and unavoidable impurities up to a total amount of 1.0% and having a specific electrical resistance at 50° C. of 0.62 to 0.65 μΩm. Also, a process for the production thereof and the use thereof in iron cores of rotating electric machines, in particular in electric motors, for example in electric vehicles or hybrid vehicles, and generators.

A hot-shapable uncoated steel-plate workpiece is press hardened by first transporting the plate through a heating zone continuously or discontinuously and there heating the plate to an austenitizing temperature while blocking entry of oxygen into the heating zone. Then the heated plate is cooled in a cooling zone to a martensitizing temperature below the austenitizing temperature without contacting the heated plate with oxygen. Finally, immediately and without cooling of the cooled workpiece to a martensite start temperature, the cooled workpiece is deformed at least partially in a finishing press into a desired shape.

A hot-shapable uncoated steel-plate workpiece is press hardened by first transporting the plate through a heating zone continuously or discontinuously and there heating the plate to an austenitizing temperature while blocking entry of oxygen into the heating zone. Then the heated plate is cooled in a cooling zone to a martensitizing temperature below the austenitizing temperature without contacting the heated plate with oxygen. Finally, immediately and without cooling of the cooled workpiece to a martensite start temperature, the cooled workpiece is deformed at least partially in a finishing press into a desired shape.

Systems and methods for heat treating closed shape workpieces are provided. In one example implementation, a method can include imparting relative motion of the closed shape workpiece such that the perimeter surface of the closed shape workpiece is moved relative to the lamp heat source from a first position where a first portion of the closed shape workpiece is presented to the lamp heat source to a second position where a second portion of the closed shape workpiece is presented to the lamp heat source. The method can include emitting lamp heat onto the perimeter surface of the closed shape workpiece from the lamp heat source during imparting of relative motion of the closed shape workpiece. The method can include implementing a flux control procedure during emitting of lamp heat onto the perimeter surface of the closed shape workpiece.

Systems and methods for heat treating closed shape workpieces are provided. In one example implementation, a method can include imparting relative motion of the closed shape workpiece such that the perimeter surface of the closed shape workpiece is moved relative to the lamp heat source from a first position where a first portion of the closed shape workpiece is presented to the lamp heat source to a second position where a second portion of the closed shape workpiece is presented to the lamp heat source. The method can include emitting lamp heat onto the perimeter surface of the closed shape workpiece from the lamp heat source during imparting of relative motion of the closed shape workpiece. The method can include implementing a flux control procedure during emitting of lamp heat onto the perimeter surface of the closed shape workpiece.

A method and an apparatus for Post Weld Heat Treatment (PWHT) of a welded aluminium alloy component and a welded aluminium alloy component treated according to the method. The welded component has initially heat affected zones with reduced load bearing capacity. The method provides that the heat affected zones are located, applying a heat source at least at one first location of said heat affected zones, where the heat source generates a temperature above T.sub.min, and where the heat source can be kept at said location for at least a period t.sub.min. The apparatus contains a heat source relatively movable with regard to the component, and further being able to be positioned on defined positions thereof, the heat source further being controllable with regard to temperature and resting time that influence the heat transferred to the component at said local position.

A method and an apparatus for Post Weld Heat Treatment (PWHT) of a welded aluminium alloy component and a welded aluminium alloy component treated according to the method. The welded component has initially heat affected zones with reduced load bearing capacity. The method provides that the heat affected zones are located, applying a heat source at least at one first location of said heat affected zones, where the heat source generates a temperature above T.sub.min, and where the heat source can be kept at said location for at least a period t.sub.min. The apparatus contains a heat source relatively movable with regard to the component, and further being able to be positioned on defined positions thereof, the heat source further being controllable with regard to temperature and resting time that influence the heat transferred to the component at said local position.

Provided are an effective and simple surface-modifying method for prolonging the life of a steel structure made of a steel material having a high sulfur (S) content, and a steel structure having a life prolonged by the surface-modifying method. A surface-modifying method for forming a friction stir region on the surface of a steel material by friction stir processing, wherein a sulfur (S) content of the steel material is 200 ppm or more.