Kawasaki Steel Corporation

Jfe Steel Corporation

Mitsubishi Jukogyo Kabushiki Kaisha

Primetals Technologies Japan, Ltd.

Sachihiro Iida

Naoto Ueno

Ichiro Tanokuchi

Takeo Fukushima

Ichiro Samejima

Hiroshi Kajitani

Kenichi Yanagi

Osamu Hashimoto

Kazumasa Mihara

Takahiro Sugano

Norihisa Shiraishi

Katsumi Makihara

Kenji Nakagawa

Yukihiko Uchiyama

Takaaki Kobashi

Motoki Imamura

Katsuhiko Kato

A steel-strip production method for producing a hot-dip-plated steel strip and a cold-rolled steel strip, the method being executed by a production apparatus including a continuous annealing furnace, a snout connected to the continuous annealing furnace, a contact-type seal plate device, a noncontact-type seal roll device, a hot-dip-plating tank being movable; and a roll configured to turn the path direction of the steel strip after passing through the snout, wherein a hot-dip-plated steel strip production unit configured to produce the hot-dip-plated steel strip by bringing the steel strip continuously annealed in the continuous annealing furnace into the hot-dip-plating tank; and a cold-rolled steel strip production unit configured to produce the cold-rolled steel strip by transferring the steel strip continuously annealed in the continuous annealing furnace without causing the steel strip to pass through the hot-dip-galvanizing tank, are configured to be switchable with one another.

Steel-strip production method, and steel strip

A steel-strip production apparatus adapted to produce a hot-dip-plated steel strip and a cold-rolled steel strip includes a continuous annealing furnace, a snout connected to the continuous annealing furnace, a contact-type seal plate device and a noncontact-type seal roll device, a hot-dip-plating tank that is movable, and a roll configured to turn the path direction of the steel strip after passing through the snout, wherein a hot-dip-plated steel strip production unit configured to produce a hot-dip-plated steel strip by bringing the steel strip continuously annealed in the continuous annealing furnace into the hot-dip-plating tank; and a cold-rolled steel strip production unit configured to produce a cold-rolled steel strip by transferring the steel strip continuously annealed in the continuous annealing furnace without causing the steel strip to pass through the hot-dip-plating tank, are configured to be switchable with one another.

Steel-strip production apparatus

Gas wiping apparatus and method can reliably prevent edge overcoat and splash, and has face gas wiping nozzles extending widthwise of a strip material, a pair of baffle plates spaced from an edge of the strip material, an edge wiping nozzle disposed between baffle plates at its inner edge and adjacent the strip material edge, all with critical spacing relative to each other.

Gas wiping apparatus and method

Gas wiping apparatus and method can reliably prevent edge overcoat and splash, and has face gas wiping nozzles extending widthwise of a strip material, a pair of baffle plates spaced from an edge of the strip material, an edge wiping nozzle disposed between baffle plates at its inner edge and adjacent the strip material edge, all with critical spacings relative to each other.

Magnetic filter device

An apparatus installed in a molten metal plating line includes a blade pressed against a roll dipped in a molten metal plating bath, in which a metal strip travels. The apparatus removes substances deposited on a surface of the roll. The apparatus also includes an arm for supporting the blade, and a screw member disposed above the plating bath so as to traverse it and moving along an axis of the roll in the bath for removing substances deposited on the roll in the molten metal plating bath. Floats and/or weights are mounted on the arm so as to adjust a press force of the blade applied to the roll in the molten metal plating bath. A method for preventing the occurrence of dents on a molten-metal-plated steel strip using the apparatus is also disclosed.

Sink roll blade apparatus used in continuous molten metal plating apparatus and method for preventing occurrence of dents

A shielding apparatus for intercepting heat from a heating source disposed in a vertical continuous annealing furnace includes a double-walled tube having an outside atmosphere suction port projected horizontally or downward to be exposed to an outside atmosphere, and an exhaust port projected upward to be exposed to the outside atmosphere.

Heat shielding apparatus for vertical continuous annealing furnace

A seal roll apparatus and method hermetically seals boundaries between a plurality of heat-treating sections for continuously heating and cooling a strip material in a continuous heat-treatment furnace. The seal roll apparatus includes a seal roll room including at least a pair of water-cooled seal rolls opposed to each other with a gap therebetween for passing the strip material, and partitions having an opening for passing the strip material, a partition being provided at the inlet side and at the outlet side of the seal rolls.

Sealing apparatus in continuous heat-treatment furnace and sealing method

A molten metal is deposited on the surfaces of a metal strip by continuously dipping the metal strip in a coating bath. The metal strip is lifted at a constant speed while supported with a pair of upper and lower support rolls in the coating bath. The coating weights of the molten metal deposited on the surfaces of the metal strip are adjusted by wiping the molten metal with gases from gas wiping nozzles disposed above the surface of the coating bath. The metal strip is advanced while supported with a pair of upper and lower touch rolls, wherein the metal strip is advanced by setting the distance L between the upper support roll disposed in the coating bath and the lower touch roll disposed outside the coating bath within the range determined by a formula L&lE;80&times;T&times;W,/V, where L: distance between the upper support roll in the coating bath and the lower touch roll outside the coating bath (mm), V: line speed of the metal strip (m/min), T: tension imposed on the metal strip (kgf/mm,), and W: target coating weight per one side of the metal strip (g/m,). The stable quality of the metal strip can be obtained by reducing the variation of the coating weights of the molten metal deposited on the surfaces of the metal strip at all times regardless of the change of the operating conditions under which continuous hot dip galvanizing operation is carried out. Further, a coating cost can be greatly reduced by preventing the excessive deposition of the molten metal.

Method of manufacturing hot dip coated metal strip

A vertical heat treating furnace for passing a metal strip, therethrough for heat treatment and a hearth roll applied to a heating/soaking furnace of the vertical heat treating furnace are disclosed. The hearth roll can be configured such that the taper angle of each of first taper sections continuous to a flat section at a central portion of the hearth roll from a roll axial direction is larger than the taper angle of each of second taper sections continuous to each of the first taper sections from the roll axial direction. The length Lc (mm) of the flat section and the length L,(mm) of the first taper section can satisfy the following relationships: 0.5 Wmin&lE;Lc&lE;Wmin and Wmin&lE;Lc&plus;2&times;L,&lE;Wmax&minus;400, where Wmin is the minimum width (mm) of the metal strip, and Wmax is the maximum width (mm) of the metal strip.

Hearth rolls for heating furnace and soaking furnace of vertical heat treating furnace and vertical heat treating furnace including hearth rolls

A continuous heat treatment furnace having one of a plurality of furnace zones except for first and last zones as a rapid cooling zone,for rapidly cooling a material by blowing an atmospheric gas, which comprises a roll-sealed chamber,partitioned at the inlet by first and second roll sealing devices,A and,B from the upstream and a third roll sealing device,C at the outlet as sealing means for atmospheric gas, and in which the inlet of the first roll sealing device and the outlet of the third roll sealing device are connected, and/or the roll-sealed chamber and an uppermost stream portion,in the rapid cooling zone are connected, and in which the hydrogen concentration in the furnace is controlled to 10% or higher in the rapid cooling zone and is controlled to 10% or lower in the furnace zone at the inlet of the rapid cooling zone. A continuous heat treatment furnace capable of simply preventing mixing of atmospheric gases in the rapid cooling zone and the atmospheric gas in the zone (heating zone, cooling zone or the like) adjacent with the rapid cooling zone of a gas jet cooling system, and a method of controlling the atmospheric gas in the furnace capable of preventing nitridation are provided.

Continuous heat treating furnace and atmosphere control method and cooling method in continuous heat treating furnace

Disclosed is an improvement of final cooling of the steel strip by immersing in cooling water, which strip has been cooled through a cooling zone in a continuous heat treating line. The improvement is achieved by injecting cooling water to the surface of the immersed strip to rapidly cool the strip to a predetermined temperature until the strip reaches the first sink-roll and resulted in that any dirt adhesion on the surface of the strip caused by contacting with the first sink-roll is prevented without increment of cooling cost.

Apparatus of cooling steel strip

A steel strip which has been cooled through a cooling zone in a continuous heat treating line is finally cooled by immersing in cooling water in a cooling tank under the controlling in accordance with the following formula:- ##EQU1## With such controlling of cooling, any dirt adhesion on the surface of the strip caused by contacting with a sink-roll is prevented.

Apparatus of cooling steel strip in continuous heat treating line

An improved method for heat-treatment of a strip in a continuous annealing installation in which the strip is heated or cooled by bringing it into contact with a heating or cooling roll having a thermal medium passed there-through. The improvements exist in that on the basis of much experimental data and mathematical analysis, a favorable range for selecting an outer diameter of a heating/cooling roll is determined as a function of various operation parameters.

Growing community of inventors

Tokyo, Japan

Sachihiro Iida