HOT BLACKENING SALT
- Hot blackening salt is a mixture of chemicals used in the hot blackening process, a method for blackening steel and iron surfaces to improve corrosion resistance and enhance appearance. The salts are typically composed of sodium hydroxide (NaOH), sodium nitrite (NaNO₂), and sodium nitrate (NaNO₃).
*. How It Works
1. Cleaning: The metal is thoroughly cleaned to remove oil, rust, and scale.
2. Immersion in Hot Blackening Salt Bath: The metal is submerged in a heated (135–150°C) alkaline nitrate-nitrite solution, which induces a controlled oxidation reaction, forming a black oxide (Fe₃O₄) layer.
3. Water Rinse: The part is rinsed to remove excess salts.
4. Sealing with Oil or Wax: A post-treatment step involves applying oil, wax, or another sealant to improve corrosion resistance.
* Common Uses
Firearms (gun bluing)
Automotive parts
Industrial machinery # Hot Blackening Salt Manufacturer.
