The production of galvanized chain is mainly divided into two major steps: first, forming the steel into a chain, and then giving the chain a "coat" of zinc. The galvanizing stage itself is further divided into two mainstream processes: hot-dip galvanizing and electro-galvanizing, each with different performance characteristics.

🔩 Step 1: Chain Base Manufacturing

1. Raw Material Preparation: Select high-quality low-carbon steel or alloy steel wire rods, which are drawn and then cut to the required length.
2. Linking & Welding: Automatic equipment bends the steel wires into rings and interlocks them to form a chain. Each link is precisely welded using flash butt welding or resistance welding technology to ensure strength and smoothness.
3. Heat Treatment: Processes like quenching and tempering are applied to enhance the chain's hardness, strength, and wear resistance.
4. Pre-straightening & Inspection: Deformations are corrected, and proof load testing (typically 2.5 times the working load limit) is conducted to ensure consistent quality for each batch.

⚡ Step 2: Galvanizing Process

· Hot-Dip Galvanizing (Superior Corrosion Resistance)
1. Pre-treatment: Alkaline cleaning to remove oil, and pickling to remove rust, revealing a clean metal surface.
2. Fluxing: Treatment with a solution like ammonium chloride to prevent secondary oxidation before galvanizing.
3. Hot-Dipping: The chain is immersed in molten zinc at 440-460°C, forming a zinc-iron alloy layer.
4. Post-treatment: Cooling and passivation treatment to further enhance corrosion resistance.
· Electro-Galvanizing (Brighter Appearance)
1. Pre-treatment: Same as above, requiring thorough cleaning.
2. Plating: The chain acts as the cathode, and zinc plates as the anode, in an electrolyte containing zinc ions. An electric current causes uniform zinc deposition.
3. Post-treatment: Removal from the bath, washing, drying, and possible additional treatments like iridescent passivation to improve appearance.

Note: Improper pickling in the electro-galvanizing process can lead to "hydrogen embrittlement," making the chain brittle and prone to breakage. Therefore, high-strength chains (e.g., those made from some alloy steels) are preferably hot-dip galvanized, or must undergo strict de-hydrogenation treatment after electro-galvanizing.

✨ Final Steps

After galvanizing, the chains undergo final inspection (appearance, dimensions, mechanical properties), followed by oiling, packaging, and warehousing.