A kind of production method of aluminum-magnesium-zinc plate steel plate

Abstract

A production method for an aluminum, magnesium and zinc coated steel plate comprises the following steps of alkali washing, water washing, acid pickling, water washing, coating auxiliary treatment, drying, hot zinc coating, cooling and finished product obtaining. According to alkali washing, NaOH, Na2CO3 and Na3PO4 are prepared into a 20%-25% solution according to the concentration of 1:1:1, alkali liquor is heated to range from 70 DEG C to 80 DEG C, and oil dirt on the surface of the steel plate is removed through the alkali liquor. Hot zinc coating liquor is prepared from, by mass percent, 50%-58% of aluminum, 1.2%-1.8% of silicon, 1%-3% of magnesium and the balance zinc. A solvent covering agent is added in the hot zinc coating process for protection, and is prepared from MgCl2, KCl and MgF2. Coating auxiliary treatment is adopted, so that the phenomena of missing coating and joint forming are reduced; and the solvent covering agent is further added in the hot zinc coating process for protection, so that aluminum, magnesium and zinc surface oxidization is avoided, and the adhesion degree of a coating layer is effectively guaranteed.

Description

technical field

[0001] The invention belongs to the technical field of hot-dip and spray coating, and in particular relates to a production method of aluminum-magnesium-zinc plated steel plate. Background technique

[0002] Al-Zn-Mg steel plate is a new type of high-corrosion-resistant coated steel plate. The galvanized layer is mainly composed of zinc, which is composed of zinc plus aluminum, magnesium and a small amount of silicon. Due to the compound effect of these added elements, its corrosion resistance is further improved. Inhibitory effect. In addition, it has excellent processing performance under severe conditions (stretching, stamping, bending, paint welding, etc.), and the coating has high hardness and excellent damage resistance. Compared with ordinary galvanized and galvalume products, it can achieve better corrosion resistance with less plating adhesion. Due to this super corrosion resistance, it can be used instead of stainless steel in some fields. [0003...

Examples

Embodiment 1

[0018] A kind of production method of aluminum-magnesium-zinc plate steel sheet, first NaOH, NaOH 2 CO 3 、Na 3 PO 4 Make 20% lye at a concentration of 1:1:1, heat the lye to 70°C, and remove the oil on the surface of the steel plate through the lye; after degreasing, wash the residual lye on the surface of the steel plate. Next, pickling is carried out. The purpose of pickling is to remove the remaining oxide scale and rust on the surface of the steel plate, so that the steel plate can obtain a smooth surface. The pickling process includes the following three aspects:

[0019] (1) Dissolution: Various iron oxides in the iron oxide scale on the surface of the steel plate react chemically with acid to form water-soluble iron salts and dissolve in the acid solution. When pickling with hydrochloric acid and sulfuric acid, ferric and ferrous chlorides and sulfates that are soluble in acid solution are generated, thereby removing iron oxide scale from the surface of the strip. ...

Embodiment 2

[0029] A kind of production method of aluminum-magnesium-zinc plate steel sheet, first NaOH, NaOH 2 CO 3 、Na 3 PO 4 Make 25% lye according to the concentration of 1:1:1, heat the lye to 80°C, and remove the oil on the surface of the steel plate through the lye; after degreasing, wash the residual lye on the surface of the steel plate with water.

[0030] Next, pickling is carried out. The purpose of pickling is to remove the remaining oxide scale and rust on the surface of the steel plate, so that the steel plate can obtain a smooth surface.

[0031] After pickling, the steel plate is washed with water to remove residual acid, iron salts, residues, etc. on the surface of the steel plate.

[0032] The cleaned steel plate should be treated with plating flux as soon as possible, mainly using 20% ​​mass concentration of zinc chloride and 20% mass concentration of ammonium chloride, adding 3% mass concentration of sodium fluoride and 3% mass concentration of fluoride Potassium,...

technical field

[0001] The invention belongs to the technical field of hot-dip and spray coating, and in particular relates to a production method of aluminum-magnesium-zinc plated steel plate. Background technique

[0002] Al-Zn-Mg steel plate is a new type of high-corrosion-resistant coated steel plate. The galvanized layer is mainly composed of zinc, which is composed of zinc plus aluminum, magnesium and a small amount of silicon. Due to the compound effect of these added elements, its corrosion resistance is further improved. Inhibitory effect. In addition, it has excellent processing performance under severe conditions (stretching, stamping, bending, paint welding, etc.), and the coating has high hardness and excellent damage resistance. Compared with ordinary galvanized and galvalume products, it can achieve better corrosion resistance with less plating adhesion. Due to this super corrosion resistance, it can be used instead of stainless steel in some fields. [0003...

Examples

Embodiment 1

[0018] A kind of production method of aluminum-magnesium-zinc plate steel sheet, first NaOH, NaOH 2 CO 3 、Na 3 PO 4 Make 20% lye at a concentration of 1:1:1, heat the lye to 70°C, and remove the oil on the surface of the steel plate through the lye; after degreasing, wash the residual lye on the surface of the steel plate. Next, pickling is carried out. The purpose of pickling is to remove the remaining oxide scale and rust on the surface of the steel plate, so that the steel plate can obtain a smooth surface. The pickling process includes the following three aspects:

[0019] (1) Dissolution: Various iron oxides in the iron oxide scale on the surface of the steel plate react chemically with acid to form water-soluble iron salts and dissolve in the acid solution. When pickling with hydrochloric acid and sulfuric acid, ferric and ferrous chlorides and sulfates that are soluble in acid solution are generated, thereby removing iron oxide scale from the surface of the strip. ...

Embodiment 2

[0029] A kind of production method of aluminum-magnesium-zinc plate steel sheet, first NaOH, NaOH 2 CO 3 、Na 3 PO 4 Make 25% lye according to the concentration of 1:1:1, heat the lye to 80°C, and remove the oil on the surface of the steel plate through the lye; after degreasing, wash the residual lye on the surface of the steel plate with water.

[0030] Next, pickling is carried out. The purpose of pickling is to remove the remaining oxide scale and rust on the surface of the steel plate, so that the steel plate can obtain a smooth surface.

[0031] After pickling, the steel plate is washed with water to remove residual acid, iron salts, residues, etc. on the surface of the steel plate.

[0032] The cleaned steel plate should be treated with plating flux as soon as possible, mainly using 20% ​​mass concentration of zinc chloride and 20% mass concentration of ammonium chloride, adding 3% mass concentration of sodium fluoride and 3% mass concentration of fluoride Potassium,...