[Object] To provide a method for cooling a steel strip in a galvannealing furnace. The method performs mist cooling on a steel strip in a cooling zone of a galvannealing furnace and can achieve both productivity and quality.

[Solution] The cooling method includes: by an adjusted cooling installation provided at an upstream side in a sheet-passing direction of the cooling installation, jetting mist to the steel strip passing through the cooling installation in a manner that an amount of mist jetted to the steel strip passing through the cooling installation is smaller in an edge portion in a width direction of the steel strip than in a center portion; by a mist suction installation provided at least at a downstream side in the sheet-passing direction of the cooling installation, sucking at least part of mist jetted to the steel strip; and cooling the steel strip at a sheet-passing speed such that, during a period between start and end of cooling of the steel strip, a temperature of the steel strip is within a film boiling temperature range and a temperature of the edge portion in the width direction of the steel strip is equal to or higher than a temperature of the center portion in at least a range of or more from the upstream side in the sheet-passing direction of a total cooling length of the cooling installation.

An apparatus (102) for processing a metal ribbon (116) comprising a main portion (118) and a sacrificial portion (120) adjoining the main portion (118) of the metal ribbon (116), is disclosed. The apparatus (102) comprises a heater (108), configured to heat the main portion (118) of the metal ribbon (116) to a first temperature, a first cooler (110), configured to cool the main portion (118) of the metal ribbon (116) from the first temperature to a third temperature lower than the first temperature, a second cooler (112), configured to cool the main portion (118) of the metal ribbon (116) at a first rate from the third temperature to a fourth temperature lower than the third temperature, a drive system (124), configured to successively advance the main portion (118) of the metal ribbon (116) from the heater (108) to the second cooler (112) through the first cooler (110), and a guide system (114) configured to route the metal ribbon (116) from the heater (108) to the second cooler (112) through the first cooler (110).

An apparatus (102) for processing a metal ribbon (116) comprising a main portion (118) and a sacrificial portion (120) adjoining the main portion (118) of the metal ribbon (116), is disclosed. The apparatus (102) comprises a heater (108), configured to heat the main portion (118) of the metal ribbon (116) to a first temperature, a first cooler (110), configured to cool the main portion (118) of the metal ribbon (116) from the first temperature to a third temperature lower than the first temperature, a second cooler (112), configured to cool the main portion (118) of the metal ribbon (116) at a first rate from the third temperature to a fourth temperature lower than the third temperature, a drive system (124), configured to successively advance the main portion (118) of the metal ribbon (116) from the heater (108) to the second cooler (112) through the first cooler (110), and a guide system (114) configured to route the metal ribbon (116) from the heater (108) to the second cooler (112) through the first cooler (110).

A heat treatment apparatus includes a furnace body and a cooling device. The furnace body has therein a processing space where a workpiece is heat-treated. The cooling device cools the processing space within the furnace body. The furnace body is provided with a first opening and a second opening. The cooling device includes an inner pipe, an outer pipe, a refrigerant supply unit, and an air supply unit. The inner pipe is provided outside the furnace body. The inner pipe couples the first opening and the second opening. The outer pipe encloses at least a portion of a periphery of the inner pipe. The refrigerant supply unit supplies a refrigerant between the inner pipe and the outer pipe. The air supply unit sends air through the inner pipe from the first opening toward the second opening.

A steel strip quenching system is provided. The system includes a lower cooling block having a quench plate and a pair of side walls defining an elongated slot configured to receive an elongated strip of steel. The system also includes a front upper cooling block mounted to the lower cooling block. The front upper cooling block has a quench plate positioned above the quench plate of the lower cooling block. The quench plate of the front upper cooling block is adjustable relative to the quench plate of the lower cooling block between a first position and a second position.

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.