Manufacturing Process For Wrought Iron Fencing

Material Cutting → Forging → Ornamental Bending → Welding & Assembly → Grinding → Hot-dip Galvanizing → Polishing →Spray Painting → Oven Baking → Decorative Finish Coating → Clear Coat Application → Packaging. Anti-rust treatment and process flow for wrought iron railings: Hot-dip galvanizing is the most effective and practical anti-rust method for wrought iron railings. It involves immersing the railing in molten zinc to form a zinc-iron alloy layer and a pure zinc layer on the surface, thereby isolating the iron from oxidation. This method offers an anti-rust lifespan of over 20 to 50 years without the need for maintenance; it is safe, reliable, and represents the optimal anti-rust solution for wrought iron products.

Hot-dip Galvanizing Process Flow
1. Pre-pickling inspection and treatment: Check the workpiece for necessary process holes (for venting, zinc flow, and suspension); assess the degree of rust and determine if surface contaminants can be removed by hydrochloric acid (contaminants such as paint or grease must be removed via burning, grinding, or alkaline washing).
2. Degreasing (Alkaline washing): Using heated equipment to remove grease, coatings, and other substances from the workpiece surface.
3. Water rinsing: Remove alkaline residue and other attached matter from the workpiece surface.
4. Pickling: Remove rust, mill scale, and other surface contaminants.
5. Post-pickling inspection and treatment: Evaluate the pickling results; repeat pickling if the initial process was insufficient, or re-treat and pickle again if pre-pickling preparation was inadequate.
6. Water rinsing: Remove acidic residue and other attached matter from the workpiece surface.
7. Flux application: Clean the workpiece surface again to ensure it does not re-rust prior to galvanizing.
8. Drying: Raise the temperature of the workpiece to eliminate excess surface moisture, preventing explosions during the galvanizing process. 9. Hot-dip galvanizing: The workpiece is immersed in molten zinc at 440°C–470°C for a specific duration before being withdrawn, resulting in the formation of a zinc-iron alloy layer and a pure zinc coating on the surface of the ironwork.
10. Passivation: Enhances the workpiece surface's resistance to atmospheric corrosion and delays the onset of white rust.
11. Cooling: Prevents rapid cooling and contraction that could cause cracking in the base metal structure.
12. Finishing: Removes zinc nodules and zinc ash adhering to the coating surface.
13. Inspection: Inspection and measurement of the coating, as well as visual examination of the workpiece.