Metal Blackening Process
* Steps in the Metal Blackening Process
1. Cleaning
Purpose: Remove all dirt, oil, grease, and existing oxides.
Methods:
Alkaline cleaning
Ultrasonic cleaning
Acid pickling
Proper cleaning ensures even coating and prevents adhesion issues.
2. Rinsing
Parts are thoroughly rinsed in water to remove cleaning residues.
Often done in multiple stages to ensure no contaminants carry over.
3. Blackening Solution Treatment
The cleaned metal is immersed in a heated blackening solution, typically a mixture of sodium hydroxide and nitrate salts.
Reaction: This chemically reacts with the metal surface to form a magnetite (Fe3O4) layer.
Temperature: Typically between 120°C to 140°C (248°F to 284°F). # Metal Blackening Chemical Manufacturer.
