The chromate polymer in the Dacromet coating on the metal surface does not contain crystal water, the coating is not easy to be damaged at high temperature, and exhibits excellent anti-corrosion performance. The corrosion resistance of parts treated with Dacromet coating on the metal surface strong ability.
In addition, Dacromet coating on the metal surface not only has high corrosion resistance, but also can ensure no hydrogen embrittlement. High-strength steel has the risk of hydrogen embrittlement in the process of pickling and electroplating, although it can be removed by heat treatment Hydrogen, but it is difficult to completely remove. The Dacromet coating process does not require pickling and activation, and does not cause electrochemical reactions that cause hydrogen evolution, which avoids the occurrence of hydrogen embrittlement.
There are many kinds of Dacromet coating liquid, but the basic composition of the coating liquid can be summarized as follows:
1. Metal objects: composed of zinc, aluminum and other substances, mainly ultrafine flaky zinc and ultrafine flaky aluminum.
2. Solvent: an inert organic solvent, such as ethylene glycol, etc.
3. Inorganic acid components: such as chromic acid, etc.
4. Special organic matter: It is the viscosity-increasing and dispersing component of the coating liquid, and the main component is cellulose-like white powder.
