Al-Zn-Mg-Si alloy for hot dipping steel

Abstract

The invention provides a rare earth-containing Al-Zn-Mg-Si alloy with high aluminum content for hot-dipping steel products, comprising the following compositions by weight percent as follows; Al: 50-75%, Mg: 1-5%, Si: 0.5-2.5%, the addition of 0.002-0.1% of Ti, 0.001-0.045% of B and 0.05-1% of rare earth (La or Ce), and the balance of Zn and unavoidable impurities. The invention utilizes corrosion resistance of Mg2Si and grain-refining effect of the rare earth, the Ti and the Bi elements to improve quality of plating solution and obtain a high aluminum content aluminum-zinc alloy cladding with ,a bright and smooth surface and great corrosion resistance property. In addition, the content of aluminum in the alloy is up to 50-75%, thereby lowering production cost.

Description

technical field [0001] The invention relates to an Al-Zn-Mg-Si alloy for hot-dipping steel, which can be widely used for steel protection in corrosive environments. Background technique [0002] Steel is easily corroded when exposed to the atmospheric environment. This problem not only brings huge economic losses to the society, but also causes great safety problems due to metal fracture and failure caused by corrosion. Therefore, countries all over the world have conducted extensive research on how to improve the corrosion resistance of steel. [0003] In recent years, the aluminum-zinc alloy hot-dip coating has been developed rapidly. It has been found that adding Mg and rare earth elements to the aluminum-zinc coating can greatly improve the corrosion resistance of the coating. The related products mainly include: Zn-6%Al-3 %Mg, Zn-11%Al-3%Mg-0.2%Si, Zn-0.2%Al-0.5%Mg, Zn-6%Al-3%Mg-RE. It can be found that most of the research on adding Mg and rare earth elements is conc...

AI Technical Summary

Problems solved by technology

For example, adding a certain amount of rare earth elements to the plating solution can purify the plating solution, reduce the viscosity of the plating solution and improve the wettability of the plating solution to the steel base, thereby greatly improving the quality of the coating, but the corrosion resistance of the rare earth to the coating is improved and the crystal grain The refinement effect of is not prominent enough

Adding a certain amount of Mg and Si elements can improve the corrosion resistance of the coating, but the resulting Mg with larger particle size 2 Si and visible Mg 2 Zn 11 It will deteriorate the surface performance and processing performance of the coating

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