C21D9/5735

Method for reducing nitrogen oxides in strip treatment furnaces

The invention relates to a method for treating metal strip in a directly fired furnace through which the metal strip is guided. The furnace is fired directly by gas burners and has a non-fired zone through which the exhaust gases from the fired zone flow and thus heat the metal strip. After leaving the non-fired zone, the exhaust gases from the furnace undergo post-combustion in an afterburner chamber. According to the invention, methane is injected into the non-fired zone, which causes nitrogen oxides contained in the waste gas to be converted into hydrogen cyanide.

METHOD FOR PRODUCING A STEEL STRIP WITH IMPROVED BONDING OF METALLIC HOT-DIP COATINGS
20210156018 · 2021-05-27 ·

A method for producing a steel strip containing, in addition to iron as the main component and unavoidable impurities, one or more of the following oxygen-affine elements in wt. %: Al: more than 0.02, Cr: more than 0.1, Mn: more than 1.3 or Si: more than 0.1, where the surface of the steel strip is cleaned, oxidation-treated and annealed. The treated and annealed steel strip is subsequently coated with a hot-dip coat. In order to be less cost-intensive and to achieve uniform, reproducible adhesion conditions for the coat, the steel strip is oxidation-treated prior to the annealing at temperatures below 200° C., where on the surface of the steel strip, with the formation of oxides with iron from the steel strip, an oxide layer is formed, which contains iron oxide and is reduction-treated during the course of the annealing under a reducing atmosphere to achieve a surface consisting substantially of metallic iron.

TEMPERATURE-CONTROL DEVICE FOR PARTIALLY COOLING A COMPONENT
20210164071 · 2021-06-03 ·

The invention relates to a temperature-control device for partially cooling a component, wherein the component is blown on with a fluid in the region to be cooled by means of a nozzle. The nozzle comprises a connecting tube which is connected to a fluid reservoir in a fluid-conducting manner and which is connected to a plurality of nozzle tubes in a fluid-conducting manner

Method for Reducing Nitrogen Oxides In Strip Treatment Furnaces
20210079494 · 2021-03-18 ·

The invention relates to a method for treating metal strip in a directly fired furnace through which the metal strip is guided. The furnace is fired directly by gas burners and has a non-fired zone through which the exhaust gases from the fired zone flow and thus heat the metal strip. After leaving the non-fired zone, the exhaust gases from the furnace undergo post-combustion in an afterburner chamber. According to the invention, methane is injected into the non-fired zone, which causes nitrogen oxides contained in the waste gas to be converted into hydrogen cyanide.

INDUCTION HEAT TREATING APPARATUS

A continuous induction heat treating apparatus is provided including a conveyor path defining an axis for a workpiece to be conveyed through the apparatus. The apparatus includes an induction heating station positioned along the conveyor path and operable to induce heating in the workpiece as the workpiece is conveyed through the induction heating station. A quenching station is positioned in a downstream direction from the induction heating station. The quenching station is coupled to a water supply and includes a plurality of sprayers in fluid communication with the water supply and operable to spray water toward the axis for quenching the workpiece as the workpiece is conveyed through the quenching station. The apparatus further includes a quench adjustment mechanism including an actuator coupled to at least a first one of the plurality of sprayers for re-positioning a point of intersection defined between the first sprayer and the axis.

Cooling equipment for continuous annealing furnace
10927426 · 2021-02-23 · ·

Cooling equipment comprising: a plurality of injection units in a continuous annealing furnace including heating zone, soaking zone, and cooling zone through which strip-shaped steel sheet is sequentially fed, the injection units arranged in cooling zone in row along feed direction of steel sheet and injecting, from injection nozzles, cooling gas containing hydrogen, onto steel sheet; and hydrogen concentration adjustment unit adjusts hydrogen concentration of cooling gas such that hydrogen concentration distribution is formed in which, in a space of the cooling zone where plurality of injection units are disposed, hydrogen concentration at upstream region is higher than hydrogen concentration at downstream region; plurality of injection nozzles arranged along feed direction of steel sheet, and each of injection nozzles extending toward steel sheet; and injection nozzles positioned at both sides in array direction inclined to slope toward a center of the array direction on progression toward tips of injection nozzles.

HIGH-STRENGTH GALVANIZED STEEL SHEET AND METHOD FOR MANUFACTURING SAME

A high-strength galvanized steel sheet includes a steel sheet having a steel composition having a specific component composition, a steel structure containing martensite and bainite at more than or equal to 70% (including 100%), ferrite at less than 20% (including 0%), and retained austenite at less than 5% (including 0%) in terms of area ratio, the amount of diffusible hydrogen in steel being less than or equal to 0.20 mass ppm; and a galvanizing layer provided on a surface of the steel sheet, having a content amount of Fe of 8 to 15% in mass %, and having an coating weight per one surface of 20 to 120 g/m.sup.2, wherein the amount of Mn oxides contained in the galvanizing layer is less than or equal to 0.050 g/m.sup.2, and a tensile strength is more than or equal to 1100 MPa and a yield ratio is more than or equal to 0.85.

Material property value estimating method, material property value estimating device, and steel-strip manufacturing method

A material-property-value estimating method of estimating a material-property-value of a target steel-strip product manufactured via at least one of a reheating process, a rolling process, and a cooling process, which are performed while a target material is being conveyed along a conveyance route, the material-property-value estimating method includes an estimating step of estimating a material-property-value of each of meshes dividing the target steel-strip product based on a measured value that has been measured once or more by a measuring device installed on the conveyance route, the measured value including at least a temperature of the target material; and a chemical composition per component of the target steel-strip product.

Method for manufacturing metal sheet and rapid quenching unit

A method for manufacturing a metal sheet comprising pinching the metal sheet in rapid quenching between a pair of pinch rolls in the range where the temperature of the metal sheet is from (T.sub.Ms+150) ( C.) to (T.sub.Mf150) ( C.), wherein the Ms temperature of the metal sheet is T.sub.Ms ( C.) and the Mf temperature thereof is T.sub.Mf ( C.), as well as a rapid quenching unit comprising a pair of pinch rolls capable of use in such a method.

COOLING APPARATUS FOR METAL STRIP AND CONTINUOUS HEAT TREATMENT FACILITY FOR METAL STRIP

A cooling device for a metal plate includes a plurality of first nozzles and a plurality of second nozzles disposed on both sides of the metal plate, respectively, in a thickness direction of the metal plate across a pass line of the metal plate. The plurality of first nozzles form a staggered array in which a pitch in a width direction of the metal plate is Xn, a pitch in a longitudinal direction of the metal plate is Yn, and an offset amount in the width direction of a pair of first nozzles disposed adjacent to each other in the longitudinal direction is Xn. The plurality of second nozzles form a staggered array in which a pitch in the width direction is Xn, a pitch in the longitudinal direction is Yn, and an offset amount in the width direction of a pair of second nozzles disposed adjacent to each other in the longitudinal direction is Xn. The staggered array of the first nozzles and the staggered array of the second nozzles are disposed offset from each other such that, a center of the second nozzle is at a position offset by a shift amount S from a center of the first nozzle in the width direction, and the center of the second nozzle is positioned in a region defined by an oval having a semi-axis of Xn/4 in the width direction and a semi-axis of Yn/3 in the longitudinal direction. The shift amount S is expressed by S=mXn/2, where m is an odd number such that S is closest to Xn/2.