Electroplating uses electrolysis to deposit a metal layer on a workpiece. The workpiece is the cathode, the plating metal is the anode, and an electrolyte solution carries metal ions.
Key parameters: Current density 1-10A/dm², bath temp 20-60°C, plating time 5-60 min.
In China, most plating shops are concentrated in designated industrial parks due to environmental regulations.
Hard Chrome: HRC65-70, excellent wear resistance. Zinc: softer, good corrosion resistance. Nickel: HRC45-55, excellent corrosion resistance. Hard chrome can be up to 0.5mm thick; zinc is typically 5-15μm; nickel 10-30μm.
Decorative chrome: copper→nickel→chrome multilayer, 0.3-1μm. Used for bathroom fixtures, hardware. Hard chrome: direct deposit 10-500μm on steel base. Used for hydraulic cylinder rods, injection screws. Key clusters: Wenzhou (Zhejiang), Jieyang (Guangdong), Cangzhou (Hebei).
Hot-dip galvanizing: 450°C molten zinc, 50-200μm coating. Cold galvanizing (electro-galvanizing): room temp, 5-15μm. Passivation: yellow or blue-white for different corrosion levels. Main producing areas: Wenzhou, Taizhou, Yongkang.
Bright nickel: mirror finish, requires copper underlayer. Used for decorative hardware. Electroless nickel: no electricity, uniform deposition even inside holes. Hardness HRC50-55. Used for automotive parts, mold cavities, oil/gas valves.