There are provided an electromagnetic wiping device, a plated steel sheet wiping apparatus including the electromagnetic wiping device, and a method for manufacturing a plated steel sheet. A portion of a plating layer of a steel sheet having passed through a plating bath is preliminarily removed at least in an edge region of the steel sheet, and a gas wiping operation is performed. Therefore, overplating is prevented at least in the edge region of the steel sheet. In addition, since the load of gas wiping can be reduced while maintaining the line speed of the steel sheet, the quantity of scattered particles and the formation of dross can be reduced for improving the plating quality of the steel sheet and the productivity of a manufacturing process.

A molten Al plated steel wire excellent in torsional resistance that does not cause breakage due to torsion in application to an ordinary production equipment for a strand wire, in which element wires are applied with torsion is provided. A molten Al plated steel wire containing a steel core wire having a diameter of from 0.05 to 0.50 mm as a core material, having thereon molten Al plating with a depositing amount thereof that is uniformized to satisfy the following expression (1) for an average diameter D.sub.A (mm) and a minimum diameter D.sub.MIN (mm) in the longitudinal direction of the wire: (D.sub.AD.sub.MIN)/D.sub.A0.10.

The invention provides a method and apparatus for coating a metal product wherein a molten coating is applied to a surface of said metal product and wherein part of said molten coating is wiped off said metal product by an air flow and a nitrogen gas flow.

The invention provides a method and apparatus for coating a metal product wherein a molten coating is applied to a surface of said metal product and wherein part of said molten coating is wiped off said metal product by an air flow and a nitrogen gas flow.

Red rust staining of Al/Zn coated steel strip in acid rain or polluted environments can be minimised by forming the coating as an AlZnSiMg alloy coating with an OT:SDAS ratio greater than a value of 0.5:1, where OT is the overlay thickness on a surface of the strip and SDAS is the measure of the secondary dendrite arm spacing for the Al-rich alpha phase dendrites in the coating. Red rust staining in acid rain or polluted environments and corrosion at cut edges in marine environments can be minimised in AlZnSiMg alloy coatings on steel strip by selection of the composition (principally Mg and Si) and solidification control (principally by cooling rate) and forming Mg.sub.2Si phase particles of a particular morphology in interdendritic channels.

Red rust staining of Al/Zn coated steel strip in acid rain or polluted environments can be minimised by forming the coating as an AlZnSiMg alloy coating with an OT:SDAS ratio greater than a value of 0.5:1, where OT is the overlay thickness on a surface of the strip and SDAS is the measure of the secondary dendrite arm spacing for the Al-rich alpha phase dendrites in the coating. Red rust staining in acid rain or polluted environments and corrosion at cut edges in marine environments can be minimised in AlZnSiMg alloy coatings on steel strip by selection of the composition (principally Mg and Si) and solidification control (principally by cooling rate) and forming Mg.sub.2Si phase particles of a particular morphology in interdendritic channels.

It is provided a method and device to control the thickness of a metallic coating on a steel wire. A device (101) for controlling a metallic coating thickness on a steel wire comprises:a digital proportional valve (113); a digital flow meter (111); a pressure sensor (115); a thickness sensor (105); a gas nozzle (119); a computer (107); and is characterized in that the relation between the gas flow measured by said digital flow meter (111) and the coating thickness measured by said thickness sensor (105) for said gas nozzle (119) is linear or parabolic.

It is provided a method and device to control the thickness of a metallic coating on a steel wire. A device (101) for controlling a metallic coating thickness on a steel wire comprises:a digital proportional valve (113); a digital flow meter (111); a pressure sensor (115); a thickness sensor (105); a gas nozzle (119); a computer (107); and is characterized in that the relation between the gas flow measured by said digital flow meter (111) and the coating thickness measured by said thickness sensor (105) for said gas nozzle (119) is linear or parabolic.

An AlZnSiMg alloy coated strip that has Mg.sub.2Si particles in the coating microstructure is disclosed. The distribution of Mg.sub.2Si particles is such that the surface of the coating has only a small proportion of Mg.sub.2Si particles or is at least substantially free of any Mg.sub.2Si particles.

An AlZnSiMg alloy coated strip that has Mg.sub.2Si particles in the coating microstructure is disclosed. The distribution of Mg.sub.2Si particles is such that the surface of the coating has only a small proportion of Mg.sub.2Si particles or is at least substantially free of any Mg.sub.2Si particles.