Stainless Steel Passivation
Stainless steel passivation is a treatment that removes free iron from the surface of a stainless steel part and forms a thin, dense protective oxide barrier.
We passivate stainless steel in accordance with ASTM A967, AMS 2700, QQ-P-35 and ASTM A380.
How Is Passivation Done?
- Degreasing and cleaning: machining oils and contaminants are completely removed; a clean surface is essential for successful passivation.
- Acid bath: free iron on the surface is dissolved with nitric acid or citric acid based solutions.
- Rinsing and drying: parts are dried without leaving chemical residues.
- Inspection: when required, results are verified with the tests defined in the standard (e.g. water immersion, humidity or salt spray tests in ASTM A967).
Why Passivation?
- Free iron picked up on the surface during machining, welding and grinding leads to rust stains; passivation prevents this.
- It ensures that the natural chromium oxide layer of stainless steel forms evenly.
- It does not change dimensions or appearance; it is suitable for tight-tolerance parts.
Applications
Defense and aerospace parts, food and medical equipment, hydraulic and pneumatic components, machined stainless steel parts. It is enough to specify the applicable standard (e.g. ASTM A967, AMS 2700) and any method/test requirement in the technical drawing. For details, read our article (in Turkish) What is passivation? .
Related services: At our facility in Ankara İvedik OSB we also offer black oxide coating and sandblasting services. You can send the technical drawing of your part via our quote form .
Guide (in Turkish): What is stainless steel passivation? ASTM A967 and AMS 2700