Provided are a steel sheet dehydrogenation apparatus, a steel sheet production system, and a steel sheet production method capable of producing a steel sheet excellent in hydrogen embrittlement resistance without changing the mechanical properties of the steel sheet. A dehydrogenation apparatus comprises: a housing configured to house a steel sheet coil obtained by coiling a steel strip; and a sound wave irradiator configured to irradiate the steel sheet coil housed in the housing with sound waves to obtain a product coil.

The invention relates to a method for removing residues present on a metal strip at the outlet of a cooling stage of a continuous line, the residues being formed during a cooling of said metal strip by a non-oxidizing liquid solution for the metal strip and a stripping liquid solution for the oxides present on the surface of the strip, or by a mixture of this liquid solution and a gas. The method according to the invention is characterized in that it comprises a step of reducing the residues by hydrogen.

An equipment for the continuous hot dip-coating of a metallic strip comprising: an annealing furnace, a tank containing a liquid metal bath, a snout connecting the annealing furnace and said bath, through which the metallic strip runs in a protective atmosphere and the lower part of said snout, the snout tip, is at least partly immersed in the liquid metal bath in order to define with the surface of the bath, and inside this snout, a liquid seal, a moveable support system, on at least one tank side, comprising connecting means, an overflow connected to said moveable support system through said connecting means, comprising at least one vat and at a least one pump.

A method comprises: annealing a steel sheet by conveying the steel sheet through a heating zone, a soaking zone, and a cooling zone in the stated order in an annealing furnace; and then applying a hot-dip galvanized coating onto the steel sheet discharged from the cooling zone. Reducing or non-oxidizing humidified gas and reducing or non-oxidizing dry gas are supplied into the soaking zone. A CO gas concentration is measured using a CO gas concentration meter provided in an exhaust portion for gas in the soaking zone. A decarburized layer thickness of the steel sheet is calculated from the measured CO gas concentration. At least one of a flow rate and a dew point of the humidified gas is controlled so that the calculated decarburized layer thickness is less than or equal to a predetermined thickness.

Disclosed is a treatment line for the continuous treatment of metal strips having a dual purpose, i.e. for producing strips that are annealed and dip-coated with a metal alloy and for producing strips that are annealed and not coated, comprising a dual-purpose cooling tower, i.e. for cooling strips that are annealed and not coated in a non-oxidizing atmosphere and for air-cooling strips that are annealed and coated.

Provided is a method of producing a hot-dip metal coated steel strip with which a hot-dip metal coated steel strip of high quality can be produced by sufficiently suppressing edge overcoating. The method comprises spraying gas from a pair of gas wiping nozzles 20A and 20B onto a steel strip S while being pulled up from a molten metal bath 14, to adjust a coating weight of molten metal on both sides of the steel strip S, wherein a pair of baffle plates 40 and 42 are respectively placed outside of both transverse edges of the steel strip, and a height B of a lower end of each of the pair of baffle plates 40 and 42 with respect to a bath surface of the molten metal bath is set to +50 mm or less, where an upper side in a vertical direction is positive.

A method for producing a metallic coated steel sheet is provided. The method includes continuously annealing a steel sheet in a continuous annealing furnace and hot dip coating the steel sheet.

The invention relates to a system and a method for hot-dip galvanizing compounds, preferably for mass-production hot-dip galvanizing a plurality of identical or similar components, preferably for batch galvaniztion.

Disclosed is a method of producing a hot-dip metal coated steel strip capable of sufficiently suppressing generation of bath wrinkles and producing high-quality hot-dip metal coated steel strip at low cost. The disclosed method of producing a hot-dip metal coated steel strip includes: blowing a gas from a pair of gas wiping nozzles 20A and 20B to a steel strip S while being pulled up from a molten metal bath 14 so as to adjust a coating weight of molten metal on both sides of the steel strip S, in which each of the gas wiping nozzles 20A and 20B includes an injection port portion that is installed downward with respect to a horizontal plane such that an angle formed by the injection port portion and the horizontal plane is 10° or more and 75° or less, and has a header pressure below 30 kPa.

The present invention provides a method for manufacturing a cold-rolled or zinc-plated dual-phase steel plate over 980 MPa. After being subjected to hot rolling, coiling, bundling, and online heat preservation, a slab is directly sent to a cold rolling and continuous annealing process, or a cold rolling, continuous annealing, and zinc plating process, so as to obtain a cold-rolled or zinc-plated dual-phase steel plate, wherein the coiling temperature is controlled to be over 450° C. The online thermal preservation means that after uncoiling of each hot-rolled coil, an independent and airtight thermal preservation cover is closed, and the hot-rolled coil with the closed thermal preservation cover is transferred to coil rolling by means of a steel coil conveying chain or a traveling car; the thermal preservation temperature for the hot-rolled coil in the thermal preservation cover is over 450° C., and the thermal preservation duration is less than 20 hours. According to the present disclosure, by means of the design of a thermal preservation process with or without a heat source after hot rolling and coiling, the manufacturing problems such as edge cracks and sharp fluctuation in thickness after cold rolling are solved, and good cold rolling manufacturability is achieved.