VCFERROUS - Hot Blackening Chemical
- Hot Blackening Chemicals for Metal Blackening
- Hot blackening (also known as black oxide coating) is a chemical process that produces a durable, corrosion-resistant black finish on steel, stainless steel, and iron. It enhances aesthetics, provides mild corrosion resistance, and reduces light reflection.
1. Hot Blackening Process & Chemicals
- Cleaning & Degreasing
- Chemical Used: Alkaline cleaner (sodium hydroxide, surfactants)
- Purpose: Removes oils, grease, and dirt to ensure proper coating adhesion.
2. Rinsing
- Chemical Used: Clean water
Purpose: Prevents contamination between process steps.
3. Acid Pickling (Descaling & Rust Removal) (if needed)
- Chemical Used: Hydrochloric acid (HCl) or sulfuric acid (H₂SO₄)
- Purpose: Removes rust, scale, and oxides from the metal surface.
4. Rinsing
- Chemical Used: Clean water
- Purpose: Ensures the surface is free of acid before blackening.
5. Hot Blackening (Oxidation Reaction)
- Chemical Used: Sodium hydroxide (NaOH) + nitrites + nitrates (oxidizing salts)
- Temperature: 135-150°C (275-300°F)
- Purpose: Reacts with iron to form a magnetite (Fe₃O₄) layer, creating the black finish.
6. Rinsing
- Chemical Used: Clean water
- Purpose: Removes excess blackening solution.
7. Sealing (Post-Treatment for Corrosion Resistance)
- Chemical Used: Oil, wax, or water-displacing sealant (e.g., mineral oil, rust inhibitors)
- Purpose: Enhances corrosion resistance and improves appearance. # VCFERROUS - Hot Blackening Chemical Manufacturer.
