Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Chromium-free passivation solution and application thereof

A chrome-free passivation and passivation tank technology, which is applied in the coating process of metal materials, can solve the problems of unstable passivation effect and high corrosion resistance of the coating, and achieve the effect of improving corrosion resistance and simple passivation process

Inactive Publication Date: 2017-12-29
GUIZHOU INST OF TECH
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the above methods mainly have the problems of unstable passivation effect, and the corrosion resistance of the coating is not as good as that of chromate passivation.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Chromium-free passivation solution and application thereof
  • Chromium-free passivation solution and application thereof
  • Chromium-free passivation solution and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Embodiment 1: the preparation of chrome-free passivation solution

[0024] (1) Dissolve 100 g of ammonium molybdate in 7 L of deionized water, add 4 g of ammonium fluorosilicate, mix well, adjust the pH value to 1.0 with 1+1 phosphoric acid solution, and obtain liquid A of the basic passivation solution;

[0025] (2) Dissolve 20.0 mg of yttrium oxide and 20.0 mg of cerium nitrate in 2L of deionized water to obtain solution B;

[0026] (3) In the passivation tank, mix liquid A and liquid B at a ratio of 1:1 (volume ratio), add water to 10L volume, adjust the pH to about 1.0, and control the temperature at 70°C±2°C to obtain a chromium-free passivation solution .

Embodiment 2

[0027] Embodiment 2: the preparation of chromium-free passivation solution

[0028] (1) Dissolve 150 g of ammonium molybdate in 7 L of deionized water, add 5 g of ammonium fluorosilicate, mix well, adjust the pH value to 2.0 with 1+1 phosphoric acid solution, and obtain liquid A of the basic passivation solution;

[0029] (2) Dissolve 40.0 mg of yttrium oxide and 50.0 mg of cerium nitrate in 2L of deionized water to obtain solution B;

[0030] (3) In the passivation tank, mix liquid A and liquid B at a ratio of 1:1 (volume ratio), add water to 10L volume, adjust the pH to about 2.0, and control the temperature at 70°C±2°C to obtain a chromium-free passivation solution .

Embodiment 3

[0031] Embodiment 3: the preparation of chrome-free passivation solution

[0032] (1) Dissolve 200g of ammonium molybdate in 7L of deionized water, add 6g of ammonium fluorosilicate, mix well, adjust the pH value to 3.0 with 1+1 phosphoric acid solution, and obtain liquid A of the basic passivation solution;

[0033] (2) Dissolve 80.0 mg of yttrium oxide and 60.0 mg of cerium nitrate in 2L of deionized water to obtain solution B;

[0034] (3) In the passivation tank, mix liquid A and liquid B at a ratio of 1:1 (volume ratio), add water to 10L volume, adjust the pH to about 3.0, and control the temperature at 70°C±2°C to obtain a chromium-free passivation solution .

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention provides a chromium-free passivation solution and a preparation method thereof. The chromium-free passivation solution is adopted to replace a medium-concentration chromate passivation solution and is specifically made of ammonium molybdate, ammonium fluorosilicate, cerium nitrate and yttrium oxide. According to chromium-free passivation solution and the preparation method thereof, the corrosion resistance of a coating subjected to chromium-free passivation treatment is equivalent to the corrosion resistance of a coating subjected to medium-concentration chromate passivation, and the requirements of greenization development of a surface treatment technology can be met.

Description

technical field [0001] The invention belongs to the technical field of surface engineering, and in particular relates to a chromium-free passivation solution suitable for electroless nickel plating on the surface of carbon steel and an application thereof. Background technique [0002] The traditional chromate passivation process can greatly improve the corrosion resistance of the electroless nickel plating layer, and is currently a widely used passivation technology for the electroless nickel plating layer in the surface treatment industry. However, the concentration of chromic anhydride (CrO3) in the passivation solution of the traditional chromate passivation process is high (about 120g / L for high chromium process; about 40g / L for medium chromium process), which makes the waste water contain toxic and harmful substances such as hexavalent chromium. "Electroplating Pollutant Discharge Standard" (GB 21900-2008) has strict restrictions on the content of hexavalent chromium a...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C23C22/44
CPCC23C22/44
Inventor 杨春
Owner GUIZHOU INST OF TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com