Silicate blue-white passivation solution and preparation method thereof

Abstract

The invention discloses a silicate blue-white passivation solution and a preparation method thereof, and belongs to the technical field of metal material surface treatment. The silicate blue-white passivation solution consists of 26-34g / L of sodium silicate, 2-4g / L malic acid, 8-12g / L sodium fluoride, 9-14mL / L hydrogen peroxide, 8-13mL / L amino trimethylene phosphonic acid and the balance water, and the pH of the silicate blue-white passivation solution is 3.0-3.5. The preparation method of the silicate blue-white passivation solution comprises the steps that sodium silicate, malic acid, sodiumfluoride, amino trimethylene phosphonic acid and hydrogen peroxide are sequentially added to deionized water and are mixed uniformly, water is added for constant volume treatment till the required volume is reached, and the pH is adjusted to 3.0-3.5 by adopting sulfuric acid, thus the silicate blue-white passivation solution is obtained. A zinc coating passivation film after the treatment by thesilicate blue-white passivation solution is blue-white, and is bright in color, the film forming is uniform, and the corrosion resistance is excellent; the silicate blue-white passivation solution isfree of trivalent chromium, sexavalent chrome and other hazardous materials, so that the silicate blue-white passivation solution is environment-friendly and pollution-free; a passivation technology is simple; the passivation efficiency is high; and the film layer corrosion resistance is good.

Description

technical field [0001] The invention relates to a silicate blue-white passivation solution and a preparation method thereof, belonging to the technical field of metal material surface treatment. Background technique [0002] Electro-galvanizing passivation process is one of the most commonly used steel anti-corrosion technologies. It is a very effective way to improve the corrosion resistance of steel. It is widely used in many fields such as automobiles, electric power, shipbuilding, aviation, machinery, construction, hardware, and home appliances. . In order to improve the corrosion resistance and bright appearance of steel products, electroplating and passivation treatment are generally carried out on them. Blue-white passivation has a simple and elegant appearance and excellent performance. It is favored by the market and has always been one of the most important post-treatment processes for galvanized parts. After treatment, the galvanized parts appear light blue and b...

AI Technical Summary

Problems solved by technology

The existing silicate system is low in cost and non-toxic, but the passivation solution is unstable and the corrosion resistance needs to be improved; the tungstate system is high in cost and poor in corrosion resistance; the molybdate system has a good effect of delaying corrosion. Low toxicity, but the requirement for film thickness is too high, and the cost is high; the rare earth metal salt system has low toxicity, good stability, and good corrosion inhibition effect, but the cost is high; the titanium salt system has high corrosion resistance, but the cost is high. High; the organic system has high corrosion resistance, but there are many types of film-forming agents, the passivation process is complicated, and the passivation cost is high