Quick alkaline galvanizing technology for plate-bending steel strip

Abstract

The invention relates to a quick alkaline galvanizing technology for a plate-bending steel strip, which comprises the following steps of: after the plate-bending steel strip is uncoiled, washing with acid, washing with water and neutralizing on a galvanization production line; and then carrying out alkaline galvanizing, washing with water, neutralizing for the second time, treating with silane, drying and rolling. Every m<3> of liquid contains the following chemical components in proportion: a neutralization liquid is prepared by adding water to 8-15 kg of sodium hydroxide; the alkaline galvanizing liquid is prepared by adding water to 200-230 kg of sodium hydroxide, 20-25 kg of zinc oxide and 10-15 L of brightener, wherein the pH value is 10-11, and the temperature is 10-38 DEG C; the secondary neutralization liquid is prepared by adding water to 4-6 kg of hydrochloric acid; and the silane treating fluid is prepared by adding water to 65-75 kg of silane and 10-15 L of methanol, wherein the temperature is 40-50 DEG C. The galvanizing coat is firm, and prevents the pollution hazard from sulfuric acid, nitric acid and chromic anhydride; and the invention has the advantages of low cost, corrosion resistance and long service life.

Description

technical field [0001] The invention relates to a metal electroplating process technology, in particular to a galvanizing process on the surface of coiled plate and strip steel. Background technique [0002] Galvanized coil strip steel is a thin steel plate widely used in industrial production. Generally, the acid galvanizing process is used to galvanize the surface of the coil strip steel. The process includes uncoiling, pickling, water washing, acid zinc sulfate galvanizing, water washing, Passivation, washing, drying, winding, acidic zinc sulfate galvanizing solution per m 3 The plating solution is prepared by adding 300-400kg of zinc sulfate, 20-30kg of boric acid, and 20kg of brightener, and adding water. 3 The passivation solution is prepared by adding 1-2kg of chromic anhydride, 2-3kg of sodium fluoride, 8-12L of nitric acid and 3-6L of sulfuric acid and adding water. This process galvanizes the surface of the coil and strip, which can enhance the anti-corrosion per...

AI Technical Summary

Problems solved by technology

At the same time, because the electroplating solution contains sulfuric acid, nitric acid, and chromic anhydride, it is easy to pollute the environment and cause great harm to the health of operators. Although protective measures can be taken to reduce pollution and harm, they cannot fundamentally solve environmental pollution and human harm.