Provided is an apparatus for cooling a metal material, the apparatus comprising: a spray cooling unit for spraying a cooling medium onto the surface of a metal material; and a spray amount control unit which regulates the rate of passage of the cooling medium sprayed from the spray cooling unit onto the edge region of the metal material, and controls the spray amount of the cooling medium.

A multipurpose continuous processing line able for heat treating and hot dip coating a steel strip comprising: an annealing section (1) for heating the steel strip to a predetermined annealing temperature and for maintaining the steel strip at said annealing temperature, a first transfer section (2), an overaging section (3) able to maintain the temperature of the steel strip between 300 C. and 700 C., a second transfer section (4) able to adjust the temperature of the steel strip to allow the hot dip coating of the strip and, a hot dip coating section (5), wherein the first transfer section (2) comprises, in sequence, cooling means (21) and heating means (22).

Embodiments of the present disclosure provides an aluminum alloy-plated steel sheet having high surface quality and weldability, a hot-formed member, and methods for manufacturing the aluminum alloy-plated steel sheet and the hot-formed member. The aluminum alloy-plated steel sheet includes: a base steel sheet; and an aluminum alloy plating layer formed on the base steel sheet, wherein the aluminum alloy plating layer includes, by weight %, Zn: 21% to 35%, Si: 1% to 6.9%, Fe: 2% to 12%, and the balance of Al and inevitable impurities.

Equipment for the continuous hot dip-coating of a metal strip 9 including an annealing furnace, a tank 2 containing a liquid metal bath 3, a snout connecting the annealing furnace and tank 2, through which the metal strip 9 runs in a protective atmosphere and the lower part of the snout, the sabot 5, is at least partly immersed in the liquid metal bath 3 in order to define with the surface of the bath, and inside this snout, a liquid seal 6, an overflow 7 not connected to the snout, the overflow 7 including at least one tray 8, placed in the vicinity of the strip 9 when entering the liquid metal bath 3 and encompassed by liquid seal 6.

Disclosed in the present invention is a steel sheet plated with a zinc-aluminum-magnesium-calcium alloy by means of hot dipping, which steel plate comprises a steel substrate and an alloy plating on a surface of the steel substrate. The chemical elements of the alloy plating include Zn and inevitable impurities, and the alloy plating further comprises the following chemical elements in percentages by mass: Al: 12-27%, Mg: 2-8%, Ca: 0.02-5%, and Si: 0.15-1.0%, wherein the mass percentage contents of Al, Mg and Ca in the alloy plating further satisfy the following relations: 4%(Mg+Ca)10%, and Al/(Mg+Ca)2.5. In addition, further disclosed in the present invention is a manufacturing method for the steel sheet plated a zinc-aluminum-magnesium-calcium alloy by means of hot dipping. The method comprises the steps of: (1) immersing a steel substrate annealed in a non-oxidizing atmosphere into a zinc-aluminum-magnesium-calcium alloy plating solution; and (2) after the plated strip steel is taken out from a plating bath pot, subjecting same to air-jet cooling by means of a cooling spray box at a cooling speed of 10 C./s until the temperature of the plated strip steel is lower than 100 C., and then placing the plated strip steel in a water quenching tank for cooling with water.

An installation for adjusting a thickness of a hot liquid coating on a traveling strip with suppression of angel wing flow defects, the traveling strip having a thickness equal to or greater than 2 mm, and for cooling the coating, the coating thickness being in a range above 25 m, the installation successively include, from a bottom upwards, on either side of the traveling strip: a wiping device having gas knives for wiping excess liquid from the coated strip at an outlet of a liquid bath; at least one conventional gas cooling header with gas blowers for solidifying the coating; and a water cooling and freezing header for producing airless spraying of demineralized water for skin freezing of the coating, the header being located as close as possible to the wiping device and between the wiping device and the at least one conventional gas cooling header.

A method for producing a high-strength hot-dip galvanized steel sheet including a steel sheet having a chemical composition containing predetermined components, with the mass ratio of Si to Mn (Si/Mn) being 0.25 or more, and the balance being Fe and incidental impurities, and a zinc coating layer formed on the surface of the steel sheet with a coating weight of not less than 20 g/m.sup.2 and not more than 120 g/m.sup.2 per one surface of the steel sheet, the method including subjecting the steel sheet to annealing and hot-dip galvanization in a continuous hot-dip galvanizing facility, wherein the maximum temperature T of the steel sheet in an annealing furnace is 900 C. or less, wherein the dew point X of an atmosphere in the furnace in the steel sheet temperature range of 700 C. to T C. is controlled to be not less than a certain temperature.

A steel-sheet non-plating defect prediction method in manufacturing equipment of a hot-dip galvanized steel sheet which equipment includes an annealing furnace, and a plating device arranged on a downstream side of the annealing furnace, the method includes: predicting steel-sheet non-plating defect information on an exit side of the manufacturing equipment by using a non-plating defect prediction model which is learned by machine learning, the non-plating defect prediction model for which an input data is data including one or two or more parameters selected from attribute information of a steel sheet charged into the manufacturing equipment, one or two or more operational parameters selected from operational parameters of the annealing furnace, and one or two or more operational parameters selected from operational parameters of the plating device, and an output data is non-plating defect information of the steel sheet on the exit side of the manufacturing equipment.