Zinc-aluminum-magnesium coating material and preparation method thereof

Abstract

The invention discloses a zinc-aluminum-magnesium coating material and a preparation method thereof, and belongs to the technical field of coating material preparation. The method comprises the following steps of firstly melting zinc and aluminum, heating to 480-490 DEG C, adding magnesium ingots in batches, adding again after the magnesium ingots added in the previous time are molten, and uniformly stirring after all the magnesium ingots are molten; sampling and detecting aluminum, magnesium and impurity elements, casting at one time after qualification, and controlling the temperature to be 510 plus or minus 5 DEG C; and after casting is completed, immediately covered the middle of the surface with a cover plate till the surface is cooled, and then carrying out water cooling. According to the method, the direct recovery rate of Mg is obviously increased, segregation is small, shrinkage cavities in the material are eliminated, and the eutectic structure of the material reaches 80% or above.

Description

technical field [0001] The invention belongs to nonferrous metal smelting, and relates to a preparation method of a coating material, in particular to a zinc-aluminum-magnesium coating material and a preparation method thereof. Background technique [0002] The corrosion resistance of zinc-aluminum-magnesium alloy coating products is 6 to 15 times that of hot-dip galvanized coatings, which makes people see the hope of greatly saving zinc resources. Especially for low aluminum alloys, the melting point of the alloy is lower than that of Galfan alloy, only about 377°C, and even 20°C-30°C lower than that of ordinary hot-dip galvanized alloys. Due to the reduction of process temperature, not only the service life of zinc pot equipment such as three-roller and six-arm is longer, but also the purpose of reducing energy consumption and cost can be achieved. Since 2010, six zinc-aluminum-magnesium alloy coating production lines have been put into commercial operation in China. At ...

AI Technical Summary

Problems solved by technology

[0003]In the booming development of zinc-aluminum-magnesium alloys, everyone has begun to study the influence of various element ratios on the coating and the mechanism of production, but it is rarely involved in the production process. Generally, the conventional alloy production method is adopted, and a variety of defects (such as element segregation, material defect, internal shrinkage cavity, etc.) are also produced, which has an adverse impact on downstream customers

In order to obtain better surface quality, a relatively high casting temperature of 550°C to 650°C is generally adopted. Magnesium is particularly prone to oxidation and burning at high temperatures, resulting in low direct yield and increased production costs. Shrinkage cavities, cracks, product breakage and other phenomena, causing safety hazards to downstream processes

In order to eliminate this defect, surface insulation is generally adopted to promote the cooling of the alloy ingot from the bottom to the top, but it causes defects such as high labor intensity, long production time, and composition segregation.

Images