A steel processing line includes a dip tub and a stab roll. The dip tub is filled with a quantity of molten metal. At least a portion of the stab roll is submerged in the quantity of molten metal. The stab roll includes two journals. Each journal is received by an opening defined by a roller sleeve including a ceramic or refractory material. The roller sleeve is disposed between each journal and a bearing block. An inner dimension of each roller sleeve and an outer dimension of each respective journal defines a clearance. The inner dimension of each roller sleeve and the outer dimension of each respective journal is configured such that the clearance persists as the stab roll and the pair of roller sleeves are heated by the molten metal. Alternatively, inserts are fastened to an outer surface of each journal in lieu of the roller sleeves.

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.

A method and a device for coating a metal strip with a coating material that is still liquid at first. During the coating, the coated metal strip runs through a roller pair. One of the rollers of the roller pair can be adjusted toward the other as a correction roller in order to eliminate a possible curvature of the metal strip. Then the metal strip runs through a blow-off apparatus for blowing off surplus coating. In order to prevent an uneven thickness distribution of the coating on the metal strip even when the correction roller of the roller pair has been adjusted, the actual position of the metal strip is controlled to a specified setpoint center position in the slot of the blow-off apparatus by an appropriate movement of the blow-off apparatus.

When a portion for measuring the plating adhesion amount reaches an upstream side position, plating adhesion amount estimation values are calculated by using a plating adhesion amount estimation expression at positions away from a position that faces the distance sensors, that is, the upstream side position, by strip-width direction distances, of the surfaces of the steel strip. When the portion for measuring the plating adhesion amount reaches a downstream side position, the strip-width direction distances of the plating adhesion amount meters are matched to the strip-width direction distances, and the plating adhesion amount actual measurement values are obtained. The plating adhesion amount estimation expression is corrected on the basis of the differences between the plating adhesion amount estimation values and the plating adhesion amount actual measurement values. Accordingly, the control accuracy of the plating adhesion amount is improved.

A continuous annealing furnace for annealing steel strips that is a vertical-type annealing furnace is configured so that part of gas inside the furnace is drawn and introduced to a refiner disposed outside the furnace including an oxygen removing apparatus and a dehumidifying apparatus, oxygen and moisture contained in the gas are removed to lower the dew point of the gas, and the gas having a lowered dew point is put back into the furnace. At least one gas inlet through which gas is drawn from the furnace into the refiner is disposed in the vicinity of the entry side of the furnace at a distance of 6 m or less in the vertical direction and 3 m or less in the furnace-length direction from the steel-strip-introduction section located at the lower part of the heating zone.

A method and arrangement for manufacturing hot dip galvanized rolled high strength steel product is presented. The method comprises providing a rolled steel product, heating and annealing the rolled steel product for creating a layer of iron oxide on the surface of the rolled steel product, cooling the rolled steel product, having the iron oxide layer, in a first cooling step to a temperature in a temperature range of 560-600° C. and holding for 3-10 seconds, quenching said rolled steel product, covered with the layer of iron oxide, in a second cooling step by immersing it into a zinc bath comprising aluminium and having a temperature between 440-450° C. for 1-5 seconds and cooling the rolled steel product in a third cooling step to room temperature. An arrangement for implementing the method is also presented.

A method for controlling surface reactions on a steel strip running through a furnace includes, successively, a first section, a second section, and a third section separated by a sealing element, an atmosphere in the second and third sections being oxidizing and reducing respectively, the method including: heating, in the first section, the steel strip to between 600 and 750° C., while causing the atmosphere therein to be slightly oxidizing and to include: an H.sub.2 content inferior to 2%; an O.sub.2 content inferior to 0.1%; an H.sub.2O or CO.sub.2, or H.sub.2O+CO.sub.2 content superior to 0.03%; a controlled dew point ranging from −50 to −15° C.; and a controlled concentration of CO+CO.sub.2 maintained below 2%. All percentages are expressed in terms of volume.

Cooling section for a steel strip continuous annealing or galvanizing line arranged to handle a metal strip (1), said section comprising at least one area (2) for dry cooling set up to project gas on said steel strip and at least one wet cooling area (5) set up to project a liquid or a mixture of gas and liquid on said steel strip.

A correction apparatus for correcting the planarity of a metal strip advancing into a coating system for coating said metal strip with a layer of molten metal, said apparatus comprising

a bridle roll, which modifies the feeding direction of the metal strip exiting an annealing furnace;

only one sink roll, arranged downstream of said bridle roll and inside a tank adapted to contain a bath of said molten metal;

a correction device for correcting the planarity of the metal strip arranged between said bridle roll and said sink roll;

wherein said correction device comprises at least two motorized rolls;

wherein a first motorized roll of said at least two motorized rolls is distal from said bridle roll in a fixed position with respect to a feeding path of the metal strip, said first motorized roll being arranged on a first side of said feeding path;

wherein said bridle roll is also arranged on said first side;

and wherein a second motorized roll of said at least two motorized rolls is proximal to said bridle roll and movable along the direction of the strip thickness, said second motorized roll being arranged on a second side, opposite to the first side, of said feeding path.

A method for producing a hot-dip galvanized steel sheet includes supplying humidified gas to the soaking zone 12 in a manner such that: in passes in which the steel sheet moves upward, the humidified gas is supplied from first humidified gas supply ports 40A to 40E provided at positions higher by 1.0 m or more and 5.0 m or less than the centers of lower hearth rolls 54 and overlapping the steel sheet in the passes when viewed from the side of the soaking zone; and in passes in which the steel sheet moves downward, the humidified gas is supplied from second humidified gas supply ports 42A to 42E provided at positions lower by 1.0 m or more and 5.0 m or less than the centers of the upper hearth rolls 52 and overlapping the steel sheet in the passes when viewed from the side of the soaking zone.