A method for hot-dip aluminum plating of steel structure parts

Abstract

The invention relates to the technical field of metal surface coatings, in particular to a hot dipping method for a steel structure. A hot dipping alloy consists of the following components in percentage by mass: 75 to 85 percent of Al, 3 to 5 percent of Mg, 3 to 5 percent of Si, 0.01 to 0.02 percent of rare earth Y, 0.04 to 0.10 percent of Ni, 0.04 to 0.10 percent of Bi, 0.04 to 0.10 percent of V, and the balance of Zn and inevitable impurities; and in the hot dipping process, a pulsed electric field is applied to a weld pool, and the parameter ranges of the pulsed electric field are that: the pulse width is 80 to 100ms, the acting frequency is 1 to 2Hz and the peak density of pulse current introduced into the weld pool is 0.1 to 10A / cm<2>. By the synergism of the rare earth Y, Ni, Bi and V, the fluidity and wettability of aluminum are improved; the strength and corrosion resistance of a coating are improved by nano Si and Mg2Si phases separated under the action of the pulsed electric field; and the pulsed electric field also has effects of refining grains and improving the compactness of the coating. By the invention, the coating quality is improved, metal consumption is reduced, a process is simple, the conventional process and equipment are mature, the cost is low and the method is worth promoting.

Description

technical field [0001] The invention relates to the technical field of metal surface coating, in particular to a hot dip coating method for steel structural parts. Background technique [0002] Corrosion is an important way of loss of steel materials. The loss of steel materials due to corrosion reaches tens of millions of tons every year. At present, hot-dip anti-corrosion coating on metal surfaces is the most effective way to improve metal corrosion resistance and reduce metal corrosion consumption; For steel materials for different purposes, due to the difference in use environment, material structure and performance, the currently used hot-dip metal coating materials mainly include: Zn series, rare earth Zn series, Zn-Al series, Al series, rare earth Al series In recent years, hot-dip aluminum plating has obvious advantages in terms of cost, environmental protection, coating performance and life, and has received more and more attention. [0003] Among the hot-dip alloy...

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Problems solved by technology

[0005] The object of the present invention is: to invent a kind of multi-element aluminum alloy that is used for the hot-dip aluminum plating of steel structure, and the hot-dip plating method that pulse electric field is applied to melt in hot-dip plating process, by optimizing the composition of multi-element alloy, in coating The formation process is the solidification process of the coating metal, which precipitates the particle phase, and controls the particle phase at the best scale that can improve the material performance through the external pulse electric field, and solves the problem that the existing technology cannot control the precipitation and growth of the precipitated phase and particles in the coating ; At the same time, the optimized hot-dip aluminum multi-element alloy introduces elements that reduce melt viscosity and surface tension to improve the hot-dip performance of aluminum alloys, thereby improving the performance and surface quality of the coating

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