Application of Nickel Chloride and Nickel Salt in Passivation of Stainless Steel

source:RUIHONG FASTENER  author:RUIHONG FASTENER release date:2021/11/12 309

Nickel chloride is often used as an activator in passivation to promote the normal dissolution of the anode and to supplement the nickel ions consumed during the passivation process. In addition to providing chloride ions for activation, nickel chloride also supplements metallic nickel. However, the price of nickel chloride is high and the production cost is high. As the activator, sodium chloride can also be used as the source of chloride ions. The accumulation of sodium ions in the passivation solution will affect the mechanical properties of the mirror layer, so it is rarely used in actual production.
is used for passivation of nickel, passivation of tin-nickel alloys, passivation of nickel-phosphorus alloys, also used in electroforming nickel, chemical passivation nickel and immersion passivation nickel solutions, and also used as passivation zinc and other additives. When using it, special attention should be paid to the content of copper, zinc and nitrate.
In the chemical polishing of aluminum alloy, adding nickel can improve the polishing quality.
The nickel passivation layer has fine crystals and is easy to polish. At the same time, the standard electrode potential of nickel is more positive than that of iron. After the nickel surface is passivated, the electrode potential is more positive, so the passivated nickel layer on the iron substrate is the cathode passivation layer. The passivation nickel layer has a high porosity, and it is basically non-porous only when the thickness of the passivation layer exceeds 25um. Therefore, a thin passivation nickel layer cannot be used alone as a protective passivation layer, but often through a combination of sensitive layers, such as copper/nickel/chromium, nickel/copper/nickel/chromium or double-layer nickel, three-layer protection/chromium To achieve the dual purpose of protection and decoration.
 Nickel salt is mainly used in surface treatment for passivation of nickel, passivation of nickel alloys, chemical passivation of nickel, chemical passivation of nickel alloys, electrolytic coloring of aluminum and alloys, and nickel salt sealing after anodization of aluminum and alloys.