A passivation solution and method suitable for improving the corrosion resistance of hot-dip galvanized steel surfaces

Abstract

The invention discloses a passivation solution and method applicable to an improvement in the hot-dip galvanized steel surface corrosion resistance. The passivation solution comprises the following components: 13-17 g / L of titanium sulfate, 8-10 g / L of nickel sulfate, 6-8 g / L of GPTMS, 0.05-0.15 g / L of nanometer silicon carbide, and the balance deionized water. The passivation method comprises thefollowing steps: putting the passivation solution in a passivation tank; adjusting the temperature and the pH value of the passivation solution; and taking a galvanized workpiece out of a hot-dip galvanizing bath, directly putting the galvanized workpiece in the passivation tank for passivation, and carrying out cleaning and drying. By adoption of the organic-inorganic combined composition as well as the composite passivation method of titanium salt, silane and nanoparticles, the thickness of a film layer can be increased, the uniform dense self-healing film layer can be acquired, and then the corrosion resistance can be improved; the environmental pollution can be reduced; after the passivation, the galvanized workpiece can be directly cleaned and dried; and the composition is simple, the cost is low, the passivation method is easy to operate, the practicability is very high, and the applicability is high.

Description

technical field [0001] The invention relates to a passivation solution and a passivation method, in particular to a passivation solution and a method suitable for improving the corrosion resistance of the surface of hot-dip galvanized steel. Background technique [0002] Hot-dip galvanizing on the surface of steel is one of the most widely used, most effective and most economical atmospheric corrosion protection methods in advanced countries. Compared with hot-dip galvanizing, the compound layer of hot-dip galvanizing is thinner, and its thickness is easy to control, so the processability is good. Hot-dip galvanized steel has been widely used in transmission line towers, communication towers, gas pipelines and other fields. After a period of use, galvanized steel is in contact with oxygen, water vapor, and other acidic or alkaline media in the air, and the surface is prone to corrosion reactions, forming zinc hydroxide or other basic zinc salts, etc., and white spots or whi...

AI Technical Summary

Problems solved by technology

Inorganic salt passivation has disadvantages such as thin film, insufficient density, poor self-healing ability, high cost of some solutions, and unsatisfactory corrosion resistance.

Organic passivation includes phytic acid, tannic acid, organic silane, etc., but there are disadvantages such as easy damage of the film layer, no self-healing ability, poor adhesion, expensive price, thin film layer, and poor corrosion resistance.

Images