Our Precision Machine Shop’s Reliable Approach to Stainless Steel Passivation
Passivation is an extremely common metal finishing process that prevents corrosion in stainless steel. About 95% of the stainless steel parts we manufacture at our shop require this treatment.
While we don’t offer this service in our precision machine shop, we’re fortunate to have an excellent joint-venture partner, Aero TMF, that excels at stainless steel passivation, making us a one-stop shop for customers who need it.
What Is Passivation for Stainless Steel?
Passivation is a chemical treatment for stainless steel that removes impurities from the metal’s surface. It’s usually the last step in the manufacturing process unless a part is being plated and/or painted.
The passivation process consists of three stages:
A degreaser removes contaminants, such as dust and other debris, that may have landed on the part during precision machining.
An acid bath (nitric acid, nitric acid with sodium dichromate, or citric acid) removes free iron. This procedure allows a chromic oxide layer to form after the part is exposed to oxygen. The passive layer protects against rust.
A final test checks the effectiveness of the passivation. Common tests include water immersion, high humidity, salt spray, copper sulfate, potassium ferricyanide-nitric acid, damp cloth, and boiling water immersion.
The chosen test depends on the passivation standard, which varies across industries. The most common standards are ASTM A967 (Standard Specification for Chemical Passivation Treatments for Stainless Steel Parts) and AMS 2700 (Passivation of Corrosion Resistant Steels).
Benefits of Passivation for Stainless Steel
Here are some of the top benefits of passivation for stainless steel:
Prevents contamination, corrosion, and defects
Extracts iron contaminants
Provides a protective finish
Increases oxide and rust resistance
Reduces the need for maintenance
Extends the life of the part
Passivation helps stainless steel parts withstand harsh environments, which is vital in industries such as pharmaceuticals, food processing, and cosmetics, where corroded equipment can cause safety issues.
Get Passivated Stainless Steel Parts from Our One-Stop Shop
When you order stainless steel parts from Alard Engineering, the passivation process is handled by our joint-venture partner, Aero TMF, and never an unknown third-party vendor.
From ordering the material to precision machining the part to passivating it, each step of the manufacturing process takes place under the Alard company umbrella, giving you the experience of a one-stop shop. As a result, you benefit from higher-quality parts, lower costs, and shorter lead times.
We know passivation is essential to protecting stainless steel parts and ensuring their longevity. Partnering with our sister company to offer this service is evidence of our commitment to high quality, close attention to detail, and satisfying customer needs.
If you need stainless steel parts, request a quote from our precision machine shop today!
