Chrome-free sealing agent

Abstract

The invention discloses a passivation sealing agent used for phosphorization or zirconiumization for a steel surface, and the passivation sealing agent does not contain chromium or other substances harmful for environment and people. The product is an aqueous solution and is composed of the following components in percentage by weight: 22-35% of silicate and metasilicate, 6-15% of sodium nitrite, 1-3% of fluozirconate and fluorotitanate, 0.1-1% of corrosion inhibitor, 0.5-2% of surfactant, 0.1-0.5% of antioxidant, 0.1-0.5% of wetting agent, pH regulator and the balance of water, wherein the pH is 7.0-9.0. The passivation sealing agent has a good passivation effect, can be used for greatly improving the antirust and anti-corrosion capability, can replace the chrome-contained sealing agent, is simple to use and has no special requirement on equipment.

Description

technical field [0001] The invention relates to a sealing agent, in particular to a chromium-free sealing agent suitable for sealing and passivation after phosphating or zirconating of iron and steel. The invention does not contain heavy metal ions such as chromium, and is a novel environment-friendly sealing agent. Background technique [0002] Since 1996, my country has been the world's largest steel producer. Over the past 10 years, China's crude steel output has grown rapidly from 108.91 million tons in 1997 to 567.84 million tons in 2009, an increase of 458.93 million tons, that is, crude steel output has increased by more than four times on the basis of 1997, and the average annual growth rate Speed ​​up to 16%. However, steel is an extremely corrosive metal. Every 90 seconds in the world, 1 ton of steel is corroded into rust, and the energy needed to refine 1 ton of steel can be used by a family for 3 months. Therefore, with the development of the steel industry, ...

AI Technical Summary

Problems solved by technology

[0006] Several chromium-free passivation products have been proposed, such as an environmentally friendly multifunctional steel surface treatment agent, application number CN200710195860.5, which cannot be used for zirconium treatment

Another example is the normal temperature film passivator and its preparation method before electrophoretic coating of iron and steel workpieces, application number CN200910187640.7, which cannot be used for zirconization treatment

In general, several chromium-free passivation products that have been proposed still exist and can only be used in the passivation of phosphating solution. They are used in new zirconium, especially silicon-free sheets, hot-rolled sheets, and iron castings in cold-rolled sheets. After zirconium treatment, it is easy to rust, and the anti-corrosion ability is reduced after spraying paint. A new passivator that can be matched with the zirconium solution is needed.