A kind of zinc-aluminum-magnesium-coated steel sheet containing tin strip and galvanizing method

Abstract

The invention relates to a tin-containing zinc-aluminum-magnesium cladded steel sheet with spangles. The size of the spangles is 3mm to 20mm, and the thickness of a double-faced cladding layer is 80g / m<2> to 300g / m<2>; the cladding layer is prepared from the following components according to the mass percent content: 1.3 to 17 percent of Al, 0.8 to 5.2 percent of Mg, 0 to 0.5 percent of Si, 0.06 to 0.3 percent of Sn, 0.03 to 0.15 percent of Fe and the balance of Zn. A zinc plating method comprises the following steps: 1) preparing zinc liquid components in percentage by mass: 1 to 15 percent of Al, 1 to 6 percent of Mg, 0 to 0.5 percent of Si, 0.06 to 0.3 percent of Sn, 0.01 to 0.1 percent of Fe and the balance of Zn and unavoidable impurities; 3) controlling the temperature of zinc liquidto be 420 to 510 DEG C, wherein the pressure of an air knife is 260mbar to 380mbar and the distance of the air knife is 10mm to 20mm; 3) feeding a sheet strip into a zinc pot at the temperature of 450 to 530 DEG C, wherein the thickness of the strip steel sheet is 0.3mm to 3.0mm and the strip speed is controlled to be 60 to 160m / min. The Sn alloy provided by the invention is used for promoting the growth of the spangles on the surface of a zinc layer, and the surface becomes more attractive; meanwhile, Al and Mg elements are added to form the zinc-aluminum-magnesium cladded steel sheet with the spangles. On the basis of ensuring that bright and attractive spangle patterns are generated on the surface of the cladded steel sheet, the corrosion resistance of the cladded steel sheet with thespangles is improved.

Description

technical field [0001] The invention relates to the technical field of hot-dip galvanizing, in particular to a zinc-aluminum-magnesium-coated steel sheet containing tin and spangles and a galvanizing method. Background technique [0002] Zinc-aluminum-magnesium-coated steel sheets have attracted more and more attention due to their higher corrosion resistance, good processability and stable coating performance. Especially in high-strength steel, due to the high content of Si and Mn, traditional hot-dip galvanizing is difficult to galvanize normally, and the increase of Al content in zinc-aluminum-magnesium increases the reactivity of Al-Fe and improves the hot-dip performance of high-strength steel. [0003] Patent CN201710294423.2 discloses an ultra-high-strength zinc-aluminum-magnesium-coated steel sheet for high-temperature forming. After hot-forming, the coating has no cracks extending to the substrate; patent CN201510548588.9 discloses a zinc-aluminum-magnesium alloy fo...

AI Technical Summary

Problems solved by technology

The patent does not describe the specific process, but only describes the composition of the coating, and the content of antimony added is relatively high. At present, the antimony content of ordinary spangle products is generally controlled at 0.08wt% to 0.1wt%, while excessively high antimony The content will cause the brittleness of the zinc layer, increase the thickness of the zinc-iron alloy layer, promote the solubility of iron in the zinc liquid, increase the iron loss, and increase the zinc consumption.

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