A method of supplying a Zn—Al alloy to a molten zinc pot which accommodates a molten zinc bath in a hot dip galvanizing line, includes: supplying the Zn—Al alloy from a supply portion provided at a lower portion of an insertion guide having a pipe shape, in which the supply portion is immersed between an inner wall of the molten zinc pot on a downstream side in a travelling direction of a steel sheet and a front support roll installed in the molten zinc bath at a depth within ±400 mm from a lower end of the front support roll, and an inside of the insertion guide is pressurized by inert gas to prevent the molten zinc bath from advancing to the inside of the insertion guide.

A method of forming an Al—Zn—Si—Mg alloy coating on a steel strip includes dipping steel strip into a bath of molten Al—Zn—Si—Mg alloy and forming a coating of the alloy on exposed surfaces of the steel strip. The method also includes controlling conditions in the molten coating bath and downstream of the coating bath so that there is a uniform Al/Zn ratio across the surface of the coating formed on the steel strip. An Al—Zn—Mg—Si coated steel strip includes a uniform Al/Zn ratio on the surface or the outermost 1-2 μm of the Al—Zn—Si—Mg alloy coating.

A method of forming an Al—Zn—Si—Mg alloy coating on a steel strip includes dipping steel strip into a bath of molten Al—Zn—Si—Mg alloy and forming a coating of the alloy on exposed surfaces of the steel strip. The method also includes controlling conditions in the molten coating bath and downstream of the coating bath so that there is a uniform Al/Zn ratio across the surface of the coating formed on the steel strip. An Al—Zn—Mg—Si coated steel strip includes a uniform Al/Zn ratio on the surface or the outermost 1-2 μm of the Al—Zn—Si—Mg alloy coating.

A method of forming an AlZnSiMg alloy coating on a steel strip includes dipping steel strip into a bath of molten AlZnSiMg alloy and forming a coating of the alloy on exposed surfaces of the steel strip. The method also includes controlling conditions in the molten coating bath and downstream of the coating bath so that there is a uniform Al/Zn ratio across the surface of the coating formed on the steel strip. An AlZnMgSi coated steel strip includes a uniform Al/Zn ratio on the surface or the outermost 1-2 ?m of the AlZnSiMg alloy coating.

The invention relates to a method for high-temperature galvanization of ferrous material parts (10). The method comprises the production of zinc melt (12). The method further comprises saturating the iron concentration of the zinc melt (12) so that it is iron-saturated. In addition, the method comprises producing an undersaturation of the iron concentration of the zinc melt (12) so that it is iron-undersaturated. The method further comprises dipping the ferrous material parts (10) in iron-undersaturated zinc melt (12), whereby a galvanization layer (14) is formed on the ferrous material parts (10).

A molten metal bath composition analysis system includes: a laser oscillator that oscillates a laser beam; a cylindrical probe that includes an opening end immersed in a molten metal bath, supplies an inert gas toward the opening end, and guides the laser beam to the opening end to irradiate a molten metal with the laser beam; and a detector that detects and spectroscopically analyzes plasma emission of the molten metal caused by the irradiation with the laser beam, wherein at least one of the position of the opening end of the cylindrical probe in the molten metal bath and the angle of the cylindrical probe with respect to a vertical direction can be controlled.