|Type of plating||Characteristic value||Uses|
|Sacrificial anti-corrosive plating (primary plating or material is electrochemically protected from corrosion by the upper-layer plating film oxidizing slowly)||- Zinc plating and zinc-based plating preventing steel materials from rusting (See zinc and zinc alloy plating.)
- Two-layer nickel plating
Potential difference by the difference of sulfur content in the Ni film based on the principle of sacrificial anti-corrosion is used.
The sulfur content in the lower layer of semigloss nickel is 0.005% and that in the upper layer of bright nickel is 0.05%. The plating thickness is approximately 20 – 30μm in total (semigloss:bright = 6:4).
The corrosion resistance of three-layer nickel plating by sandwiching bright nickel containing 0.1 – 0.2% sulfur between the two layers of plating is further improved.
|Various metal products|
|Plating with good corrosion resistance in plating films themselves||- Plating with noble metals small in ionization tendency, such as gold, platinum, rhodium, and palladium.
- Chemical-resistant electroless nickel plating, chromium plating, nickel-tungsten alloy plating, etc.
The high corrosion resistance of nickel-based alloy plating originates in the passivation phenomenon of films.
|Chemical industry equipment|