Be and multi-combination degenerative low-zinc hot-dipped aluminum alloy coating material and preparation method thereof

Abstract

A low-zinc hot dip aluminum alloy coating material containing Be and a combination of agents and a preparation method thereof. The alloy coating material comprises, by weight percent of the elements, Zn of less than 30, Be of 10-4 to 0.05, alloy strengthening agent of 10-4 to 6.0, solvent passivating agent of 10-4 to 1.0, precipitation hardening agent of 10-4 to 0.5, crystal grain size reducing agent of 10-4 to 1.0, rare earth additive of 10-4 to 1.0, and substrate-interface reaction buffer of 0.001 to 2.0, with the remainder being Al and inevitable trace impurities.

Description

technical field [0001] The invention relates to an aluminum alloy coating material and a preparation method thereof, in particular to a low-zinc hot-dip aluminum alloy coating material modified by combination of Be and multiple components and a preparation method thereof. Background technique [0002] At present, there are more than 400 galvanizing lines that have been put into operation in the world, covering more than 60 countries. The output of galvanized steel products is close to 200 million tons, most of which are galvanized steel sheets. Since the annual consumption of zinc for hot-dip galvanizing in the world reaches more than 70% of the total output of zinc metal, the shortage of zinc resources is becoming more and more severe. Since 2008, the world's zinc production has maintained an average of about 12 million tons per year, and the consumption of the hot-dip galvanizing industry has reached more than 8.5 million tons, while the coverage of galvanized steel produc...

AI Technical Summary

Problems solved by technology

Galvalume is a U.S. patent with a composition of 55%Al-43.4%Zn-1.6%Si. It is a high-aluminum zinc alloy coating material that has been practically industrialized at present, although its ability to protect the steel base is 2-2% that of pure zinc coatings. 7 times, and can save a lot of zinc resources, but due to the high immersion temperature (590 ~ 600 ℃), the poor wetting ability of the plating solution to the steel base, it is easy to produce needle-shaped missing plating of the steel plate, and the cathodic protection of the coating to scratches and cuts Insufficient capacity, forming processing, welding and coating performance, etc. have gaps with pure zinc coatings, which offset many advantages and make it not well accepted by the market.

Galfan is a 5% Al-Zn system coating material developed in Belgium. It contains trace elements such as Fe, Si, Pb, Cd, Sn and rare earth. Its melting point is lower than that of pure zinc, which solves the problem of the wetting ability of Galvalume plating solution to steel base The poor problem relies on the rapid cooling of the steel plate to produce a fine eutectic structure, so the coating has higher corrosion resistance than zinc and good coating performance, processing performance and weldability, but due to Pb, Cd, Sn, etc. Low-melting-point metals are prone to cause intergranular corrosion of the coating (causing color changes), have strict restrictions on the cooling rate of the steel plate, and the coating is prone to large-scale pits and poor high-temperature oxidation resistance, which affect the market application of Galfan. On the surface, it still contains more than 90% Zn, which is of little significance in saving zinc resources and cannot solve the problem of long-term development of the hot-dip galvanizing industry

In recent years, Zn-Al-Mg and multi-system alloy coating materials with related components have emerged. The United States has Zn-Al-Mg-Ti-B-Si and Zn-Al-Mg-Si patented products; Japan has aluminum content 5 %~12% hot-dip galvanized alloy sheet, Zn-Al-Mg-Si, Zn-Al-Mg-Si-Mn-Cr and Zn-Al-Mg patents, etc., but the aluminum content of these new products and patents is mostly Below 50%; and there is basically no patented technology for new coating materials that can achieve low-cost industrial applications

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