Energy-efficient production of a ferritic hot-rolled strip (6) in an integrated casting-rolling plant (1), which modifies the known processes for producing a ferritic hot-rolled strip (6) in an integrated casting-rolling plant (1) so that the ferritic hot-rolled strip (6) can be produced significantly more energy-efficiently but nevertheless has good metallurgical properties and a good surface quality.

A process for secondary descaling of running metal strips, especially made of steel, during hot-rolling by-spraying water onto the surface of the running metal strips with spray rails having nozzles supplied with pressurized water, wherein the nozzles are supplied at a hydraulic pressure of from 3 to 30 bar, and wherein the nozzles are regulated so that heat flux density extracted from the strip (HF) resulting from the cooling of its surface by the sprayed water is between 6.5 and 20 MW/m.sup.2 for a strip temperature between 900 and 1100 C.

Energy-efficient production of a ferritic hot-rolled strip (6) in an integrated casting-rolling plant (1), which modifies the known processes for producing a ferritic hot-rolled strip (6) in an integrated casting-rolling plant (1) so that the ferritic hot-rolled strip (6) can be produced significantly more energy-efficiently but nevertheless has good metallurgical properties and a good surface quality.

The present invention relates to a method for the cleaning and/or anti-corrosion pretreatment of a plurality of components in series, in which the components of the series are at least partially composed of zinc-coated (ZM) steel. After a cleaning stage and before further cleaning and/or anti-corrosion pretreatment, the components pass through a treatment stage for improving the wettability of the zinc-coated (ZM) steel surfaces in which at least the surfaces of the zinc-coated (ZM) steel of the components are brought into contact with an aqueous medium which contains at least one builder which is a salt of a Lewis acid-base pair in which the Lewis acid is selected from Li.sup.+, Na.sup.+, K.sup.+, Ca.sup.2+, Mg.sup.2+ or Al.sup.3+, and the Lewis base is selected from anions of a polyprotic Br?nsted acid.

[Object] To provide a liquid removal device capable of removing liquid on a steel sheet without using wringer rolls and a drier.

[Solution] A liquid removal device that removes liquid attached to a surface of a sheet-like member that moves relatively, the liquid removal device including: a slit nozzle that jets gas to the surface of the sheet-like member; and a gap measurement device that measures a gap between a jetting port of the slit nozzle and the sheet-like member. The slit nozzle is installed so as to jet gas from a downstream side toward an upstream side in a movement direction of the sheet-like member that moves relatively to the slit nozzle, and is configured in a manner that a jet angle , a back face inclination angle , a back face length L of a nozzle back face, a gap h, a slit width d, and nozzle pressure P.sub.n of the slit nozzle satisfy the following relational formulas.

[00001]$\begin{array}{cc}{P}_{n}2.0{10}^{10}.Math.{\left(h.Math.\text{/}.Math.d\right)}^{0.6}.Math.{\left(\frac{1}{1+\exp \left(+-58\right)}+1\right)}^{-4}.Math.L^{-7},+60.Math.,L20.Math..Math.\mathrm{mm}& \left[\mathrm{Math}..Math.1\right]\end{array}$

Disclosed is a method for continuous thermal treatment of 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.

Disclosed is a method for continuous thermal treatment of 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.

Methods and systems are provided for treating oxide scale on the surface of a metal object. In one embodiment, a system temperature control apparatus controls the temperature of metal object's surface to an application temperature below the Leidenfrost temperature point of an alkali metal hydroxide aqueous conditioning solution. An application apparatus wets the metal object's surface at the controlled temperature with a thin layer of the solution that engages the oxide scale, and a heating apparatus heats the wetted surface to a final conditioning temperature above a melting point of the alkali metal hydroxide by an additional value selected to effect conditioning of the oxide scale at a reasonable but not excessive rate by the melting alkali metal hydroxide reacting with the oxide scale. The system terminates additional conditioning to prevent creation of additional oxide scale beyond the conditioned depth.

A rotating drum of a rotating drum-type workpiece cleaning device is provided with feed fins that extend helically along the inner circumferential surface of the drum body. The feed fins are, for example, fins in which metal sheets have been folded. On both sides of the feed fins, the angle of the internal corner between the feed fin and the inner circumferential surface of the drum body is an obtuse angle, for example, about 120 degrees. It is possible to prevent or limit the trapping of conveyed workpiece in the internal corner and trapping between adjacent fin sections.

The present invention relates to a method for the cleaning and/or anti-corrosion pretreatment of a plurality of components in series, in which the components of the series are at least partially composed of zinc-coated (ZM) steel. After a cleaning stage and before further cleaning and/or anti-corrosion pretreatment, the components pass through a treatment stage for improving the wettability of the zinc-coated (ZM) steel surfaces in which at least the surfaces of the zinc-coated (ZM) steel of the components are brought into contact with an aqueous medium which contains at least one builder which is a salt of a Lewis acid-base pair in which the Lewis acid is selected from Li.sup.+, Na.sup.+, K.sup.+, Ca.sup.2+, Mg.sup.2+ or Al.sup.3+, and the Lewis base is selected from anions of a polyprotic Brnsted acid.