Disclosed is a continuous thermal treatment line for a steel strip. The strip passes through consecutive thermal treatment chambers, is quickly cooled in at least one of the chambers by spraying liquid onto the strip, or by spraying a fluid made up of gas and liquid or spraying a combination of gas and liquid forming a mist. After quick cooling, a protective metal layer is deposited on the strip by dip coating. The cooling fluid strips iron oxides or other alloy elements contained in the steel to be treated, minimizing oxidation and reducing the oxides on the strip. Spray pressure and distance are chosen to facilitate the stripping property and the mechanical action of the sprayed fluid, reducing the layer of oxides on the strip. The temperature of the strip at the end of the cooling step is the temperature necessary for carrying out the desired treatment cycle.

The invention relates to a method for cooling a metallic item (1) by discharging a cooling medium from a cooling bar (2) onto the item (1), wherein the cooling medium is discharged through a slot (3) in the cooling bar (2). According to the invention, in order to achieve improved cooling, during the cooling process the width (B) of the slot (3) in the conveying direction (F) of the item (1) or of the cooling bar (2) is altered in order to bring the cooling power of the cooling medium to a desired or predefined level by open-loop or closed-loop control. In addition, the invention relates to a cooling bar.

The invention relates to a method for cooling a metallic item (1) by discharging a cooling medium from a cooling bar (2) onto the item (1), wherein the cooling medium is discharged through a slot (3) in the cooling bar (2). According to the invention, in order to achieve improved cooling, during the cooling process the width (B) of the slot (3) in the conveying direction (F) of the item (1) or of the cooling bar (2) is altered in order to bring the cooling power of the cooling medium to a desired or predefined level by open-loop or closed-loop control. In addition, the invention relates to a cooling bar.

The invention relates to a component in the form of a wheel comprising: a hub portion, a rim portion with an outer rim flange and an inner rim flange, a plurality of circumferentially distributed spokes extending between the hub portion and the rim portion, wherein the spokes and the hub portion are arranged offset with respect to a wheel center plane towards the outer rim flange and have an inner side facing the wheel center plane and an outer side directed away from the wheel center plane, wherein the outer rim flange has greater tensile residual stresses at least in a partial region than at least a partial region of the inner rim flange.

Disclosed are implementations for heat treatment of steel components. In one or more first regions of a steel component, a predominantly austenitic structure can be adjusted, from which, by way of quenching, a mainly martensitic structure is educible. In one or more second regions of the steel component, there is a mainly bainitic structure, wherein the metal component is initially heated in a first furnace to a temperature above the Ac3 temperature. Subsequently, the steel component is transferred into a treatment station, wherein the steel component can cool down during the transfer. In the treatment station, the one or more second regions of the steel component are cooled down to a cooling stop temperatures ϑ.sub.2 during a treatment period. Subsequently, said metal component is transferred to a second furnace, wherein the temperature of the one or more second regions increases again to a temperature below the Ac3 temperature.

Disclosed are implementations for heat treatment of steel components. In one or more first regions of a steel component, a predominantly austenitic structure can be adjusted, from which, by way of quenching, a mainly martensitic structure is educible. In one or more second regions of the steel component, there is a mainly bainitic structure, wherein the metal component is initially heated in a first furnace to a temperature above the Ac3 temperature. Subsequently, the steel component is transferred into a treatment station, wherein the steel component can cool down during the transfer. In the treatment station, the one or more second regions of the steel component are cooled down to a cooling stop temperatures ϑ.sub.2 during a treatment period. Subsequently, said metal component is transferred to a second furnace, wherein the temperature of the one or more second regions increases again to a temperature below the Ac3 temperature.

A side spray method for cooling a steel strip after hot rolling includes providing side spray devices behind multiple cooling sections on two sides in a width direction of a run out roller table of the steel strip after hot rolling. The side spray devices are staggered along the two sides of the run out roller table of the steel strip, the side spray devices include at least two spray units, each spray unit includes a spray tube and nozzles on the spray tube, the spray tubes being in parallel and vertically arranged along a running direction of the steel strip, and being movable along the running direction of the steel strip, covering ranges of the nozzles on the side spray devices are partially overlapped with each other, and a total spray coverage covering of nozzles covers a width of the run out roller table of the steel strip.

A side spray method for cooling a steel strip after hot rolling includes providing side spray devices behind multiple cooling sections on two sides in a width direction of a run out roller table of the steel strip after hot rolling. The side spray devices are staggered along the two sides of the run out roller table of the steel strip, the side spray devices include at least two spray units, each spray unit includes a spray tube and nozzles on the spray tube, the spray tubes being in parallel and vertically arranged along a running direction of the steel strip, and being movable along the running direction of the steel strip, covering ranges of the nozzles on the side spray devices are partially overlapped with each other, and a total spray coverage covering of nozzles covers a width of the run out roller table of the steel strip.

A heat treatment apparatus that thermally treats an annular workpiece formed of a steel material by inductively heating the workpiece includes a treatment tank in which the workpiece is set and thermally treated, a holding portion that holds the workpiece at a predetermined position, an induction heating coil that surrounds the workpiece to inductively heat the workpiece, and a cooling medium that cools surfaces of the workpiece during the induction heating of the workpiece.

A heat treatment apparatus that thermally treats an annular workpiece formed of a steel material by inductively heating the workpiece includes a treatment tank in which the workpiece is set and thermally treated, a holding portion that holds the workpiece at a predetermined position, an induction heating coil that surrounds the workpiece to inductively heat the workpiece, and a cooling medium that cools surfaces of the workpiece during the induction heating of the workpiece.