Zinc-aluminum-magnesium coated steel plate with excellent adhesive performance and manufacturing method thereof

Abstract

The invention discloses a zinc-aluminum-magnesium coated steel plate with excellent adhesive performance. The zinc-aluminum-magnesium coated steel plate with excellent adhesive performance comprises a steel plate and a zinc-aluminum-magnesium coating; the zinc-aluminum-magnesium coating sequentially comprises a surface layer, a secondary surface layer and a mother layer from outside to inside; the surface layer is provided with oxides of Al and Mg; the secondary surface layer is provided with a Zn / MgZn<2> binary eutectic phase and a Zn / Al / MgZn<2> ternary eutectic phase; and the mother layer adjacent to the steel plate; wherein the contents of Al and Mg elements of the surface layer are respectively not higher than 1.5 times of the contents of Al and Mg elements of the mother layer, and the contents of Al and Mg elements of the secondary surface layer are respectively not higher than 0.5 times of the contents of Al and Mg elements of the mother layer. In addition, the invention also discloses a manufacturing method of the zinc-aluminum-magnesium coated steel plate, which comprises the following steps: (1) steel plate pre-treating; (2) hot dipping; (3) cooling after plating: cooling to 40-200 DEG C, and carrying out the following step (4); and (4) coating surface treatment: carrying out alkaline activation treatment on the coating surface by adopting an alkaline aqueous solution.

Description

technical field [0001] The invention relates to a steel plate and a manufacturing method thereof, in particular to a coated steel plate and a manufacturing method thereof. Background technique [0002] Zinc-aluminum-magnesium coating is a coating with higher corrosion resistance than pure zinc coating. In addition to Zn, the coating also contains a certain amount of Al and Mg elements. Therefore, zinc-aluminum-magnesium-coated steel sheets are not only widely used in the construction industry The application, and the application in the automotive industry has gradually increased in recent years. Due to the high corrosion resistance of zinc-aluminum-magnesium-coated steel sheets, it can not only improve the corrosion resistance of the vehicle, but also reduce the thickness of the coating compared to pure zinc-coated steel sheets, which also contributes to the lightweight of automobiles. In addition, the hardness of zinc-aluminum-magnesium-coated steel sheets is higher than t...

AI Technical Summary

Problems solved by technology

However, it should be pointed out that the fluorine-containing aqueous composition used in this technical solution is prepared from NaF or NaHF2, and the above two substances have great harm to the environment

[0009]Based on this, it is expected to obtain a zinc-aluminum-magnesium coated steel sheet with excellent adhesive properties, which can well solve the problem of the zinc-aluminum-magnesium coated steel sheet in the prior art. The problem of poor performance has an important and positive impact on accelerating the application of zinc-aluminum-magnesium-coated steel sheets in the automotive industry and further improving the corrosion resistance of automobiles

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