Inactivating process of galvanized steel sheet and inactivating liquid thereof

A technology of galvanized steel sheet and passivation solution, applied in the direction of metal material coating process, etc., can solve the problems of poor adhesion between paint and galvanized steel sheet, poor passivation effect, long passivation time, etc., to achieve good adhesion, Small investment, friendly to the environment and human body

Inactive Publication Date: 2008-05-21
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Patent CN1974842A (for the anti-white rust passivation liquid of galvanized layer and coating method thereof) proposes the new method that adopts the mixed solution of molybdate and silane coupling agent to carry out passivation to zinc, but the passivation effect of this method is relatively low. Poor, the corrosion area of ​​the passivated galvanized layer reaches 1-8% after 8 hours of neutral salt spray test
[0004] Chinese patent CN1754985A discloses a metal surface passivator and its application method, CN1754986A discloses a metal surface passivator, and CN1715448A discloses a metal surface passivator, using hydrazine, cyclohexylamine, zinc sulfate , trisodium phosphate, etc. to passivate the metal surface including zinc, but the passivation time of this method must be more than 20 hours, and the efficiency is low
Therefore, most of the currently developed chromate-free passivation technologies have shortcomings such as poor corrosion resistance, long passivation time, and poor adhesion between paint and galvanized steel sheets. Chromium passivation process

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] The amount of galvanizing produced by Hunan Lianyuan Iron and Steel Plant is 20g / m 2 , a cold-rolled galvanized steel sheet with a thickness of 0.8mm. The galvanized steel sheet has been degreased on the surface, the size is 30mm×30mm, and the surface is coated with 20mL / L r-aminopropyltriethoxysilane aqueous solution at 25°C. , dried with hot air at 50°C and then immersed in passivation solution at 45°C, the passivation solution formula is: Ce(NO 3 ) 3 15g / L, La(NO 3 ) 3 0.5g / L,H 2 o 2 20mL / L, HBO 3 0.5g / L aqueous solution, adjust its pH value to 1.0 with sulfuric acid, soak for 55 seconds, and then dry it with hot air at 50°C. Three test pieces of the passivated test piece and the cold-rolled galvanized sheet test piece without passivation treatment were respectively taken for neutral salt spray test and cross-cut test. The results are as follows:

[0020] 1) In the salt spray test, obvious white rust appeared on the surface of the unpassivated test piece a...

Embodiment 2

[0023] The amount of galvanizing produced by Hunan Lianyuan Iron and Steel Plant is 20g / m 2 , a cold-rolled galvanized steel sheet with a thickness of 0.8mm. The galvanized steel sheet has been degreased on the surface, the size is 30mm×30mm, and the surface is coated with 50mL / L r-aminopropyltriethoxysilane aqueous solution at 40°C. , dried with hot air at 60°C and then immersed in passivation solution at 50°C, the formula of passivation solution is: Ce(NO 3 ) 3 20g / L, La(NO 3 ) 3 1g / L,H 2 o 2 30mL / L, HBO 3 2g / L aqueous solution, adjust its pH value to 1.6 with sulfuric acid, soak for 60 seconds, and then dry it with hot air at 60°C. Three test pieces of the passivated test piece and the cold-rolled galvanized sheet test piece without passivation treatment were respectively taken for neutral salt spray test and cross-cut test. The results are as follows:

[0024] 1) In the salt spray test, obvious white rust appeared on the surface of the unpassivated test piece af...

Embodiment 3

[0027] The amount of galvanizing produced by Hunan Lianyuan Iron and Steel Plant is 20g / m 2 , a cold-rolled galvanized steel sheet with a thickness of 0.8mm. The galvanized steel sheet has been degreased on the surface, the size is 30mm×30mm, and the surface is coated with 90mL / L r-aminopropyltriethoxysilane aqueous solution at 55°C. , dried with hot air at 70°C and then immersed in passivation solution at 55°C. The formula of passivation solution is: Ce(NO 3 ) 3 25g / L, La(NO 3 ) 3 2g / L, H 2 o 2 40mL / L, HBO 3 4g / L aqueous solution, adjust its pH value to 2.0 with sulfuric acid, soak for 65 seconds, and then dry it with hot air at 70°C. Three test pieces of the passivated test piece and the cold-rolled galvanized sheet test piece without passivation treatment were respectively taken for neutral salt spray test and cross-cut test. The results are as follows:

[0028] 1) In the salt spray test, obvious white rust appeared on the surface of the unpassivated test piece a...

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PUM

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Abstract

The invention discloses a passivation technique for a galvanized steel sheet and a passivation solution thereof. The r-aminopropyl-triethoxysilane water solution is applied onto a clean galvanized steel sheet surface. After the steel sheet is dried with the hot air, the sheet is immersed in the passivation solution. Finally, the sheet is dried again with the hot air. The passivation technique of the invention is simple, the passivation time is quite short, and the passivation effect is almost the same with that of the chromium passivation technique, so the invention is suitable for spreading and application.

Description

technical field [0001] The invention relates to the field of metal material surface treatment. The invention relates to the field of metal material surface treatment, in particular to a metal surface passivation solution and a passivation process. Background technique [0002] Galvanized steel sheets are widely used in industries such as automobiles, construction, and home appliances. When the galvanized steel sheet without passivation treatment is exposed to the air, it is easy to produce white rust on the surface, which will affect the appearance and service life of the product. In order to avoid the generation of white rust on the surface, the traditional passivation treatment of galvanized steel sheets mostly uses hexavalent chromium compounds such as chromic acid and chromate as the treatment agent. This process can form a layer containing Cr3 on the surface of galvanized steel sheets. + and Cr6 + The passivation film layer with excellent corrosion resistance and self...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C23C22/50C23C22/78
Inventor 满瑞林徐斌彭天兰
Owner CENT SOUTH UNIV
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