Technical advantages of Dacrol (zinc chromium coating)

"Dacromet" is a kind of new structure and performance protective layer formed by sintering by coating liquid composed of flake zinc powder, aluminum powder, metal salt containing chromium and binder coated on the surface of parts. Its English name is "Dacromet". The related standard of our country is called "zinc chromium coating".

Dacrol anticorrosive technology advantages

1) Good corrosion resistance. The thickness of dallol film is only 4~8μm, but its antirust effect is more than 7~10 times that of traditional electrogalvanizing, hot dipping zinc or coating. After 100h salt spray test, only 1μm of Dallol film was corroded. The standard parts and pipe joints treated by Dallol process did not show red rust after 1200h salt spray test.

2) High heat resistance. Dacrol coating is sintered at 300℃, which can be used for a long time in high temperature environment and maintain good appearance and corrosion resistance. Even at 500℃ Dacrol film also maintains its good stability, heat resistance and corrosion resistance.

3) No hydrogen embrittlement. Hydrogen embrittlement is a problem existing in traditional electroplating anticorrosion technology. In the process of Dacrol treatment, there is no need for pickling or any electrolytic process, and it needs to be cured at 300℃ to eliminate all possible paths of H+ erosion of steel matrix, so there will be no hydrogen embrittlement in Dacrol coating.

4) High permeability. Due to its water-soluble properties, the parts with complex shapes can also be impregnated with paint, and a complete and uniform dacrol coating can be formed after sintering.

5) Good binding force with other coatings. Due to its special coating surface state, Dacrol coating has good binding force with other coatings, and the binding force with organic coating even exceeds that of phosphating film, so it is very suitable for surface recoating.

6) Excellent weather resistance and chemical resistance. Dacro-treated parts can be used for a long time in Marine environment, industrial areas and areas with serious air pollution without corrosion. In addition, it has good chemical stability to various cleaners, oils, acids, alkalis and so on.

7) Improve friction performance. Adding polytetrafluoroethylene (PTFE) into Dacrol treatment solution can obviously improve the tribological properties of Dacrol film, which is particularly important for bolt fasteners. Because its friction factor has a direct effect on the pretightening force of bolt.

8) Relatively good environmental protection. Compared with traditional electroplating technology, dacrol treatment technology can reduce environmental pollution to a certain extent, especially after the popularization of Dacrol coating formula without Cr6+, its environmental protection advantages are more obvious.

At present, Dacrol has been used in electric power, construction, Marine engineering, household appliances, hardware and standard parts, railway, bridge, tunnel, highway guardrail, petrochemical, biological engineering, medical instruments powder metallurgy and other industries.