What is Passivation?
Passivation is a chemical cleaning process that is designed to remove free iron and other ferrous contaminants from the surface of stainless steel parts. By removing the contamination from machining, stamping, etc., you are helping restore the material to the original mill condition and corrosion specifications.
Passivation is ideal for many grades of stainless steel that have adequate levels of chromium and nickel, and it can help increase the longevity of many types of metal parts.
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Why choose the Able Electropolishing Company?
- ABLE Electropolishing has been in business since 1954 and is a trusted source in the metal finishing industry. Our customers cover a wide array of industries including: aerospace, medical, dental, pharmaceutical and food processing, to name a few.
- Our state of the art 40,000 square foot facility gives us the ability to process one part to thousands of parts in a timely manner. Learn more about our Capabilities.
- ABLE has the capacity to passivate both small and large parts. Our largest tank measures 48” x 59” x 107”.
- We offer expedited service at our centrally located facility that operates 24 hours a day, five days a week with three equally staffed shifts.
- ABLE passivates in accordance with ASTM A967, AMS 2700, ASTM A380 and ASTM F86, as well as, many other industry and customer-specific standards
Is Passivation the Right Process?
- Several popular grades of stainless steel should not be passivated due to low levels of chromium and nickel. When passivated, you run the risk of flask attack occurring which weakens the base material and does irreparable damage to the part.
- Welded or brazed parts are not recommended for passivation. The process is not capable of removing the scale and discoloration in the “heat affected zone”.
- As an alternative to passivation, your part may be better suited for our proprietary Brite Passivation process. This process involves a light electropolish, which is a superior process to passivation for improving corrosion resistance.
- Please contact our sales department at email@example.com with questions on which process is best for your application.
How the Passivation Process Works
Passivation is a chemical process designed to increase the corrosion resistance of stainless steel parts.
During the passivation process, parts are placed in a basket and submerged in a nitric or citric acid bath. Depending on the stainless steel alloy, the acid concentration, temperature and time are set to effectively remove free iron and other foreign materials on the part’s surface introduced during machining, stamping, and other processes. The passivation leaves the part clean and more corrosion resistant but does not change the aesthetics of the part.
If improved corrosion resistance is the ultimate goal, passivation is an efficient process that parts can undergo, but passivation alone is not always effective at removing surface contaminants, and frequently requires an additional pre-cleaning step. However, electropolishing can remove all traces of surface and embedded contaminants in one operation.
Passivation is also only ideal for certain grades of stainless steel to remove free iron and other contaminants, but it isn’t recommended for some stainless steel grades that have insufficient levels of nickel and chromium. Welded or brazed parts are also incapable of undergoing the passivation process.
You can speak with an expert at Able Electropolishing to determine if your parts are ideal for passivation or other processes such as electropolishing. You may also find that your parts require more thorough microfinishing than passivation can provide.
A Commitment to the Environment
Over the years, Able has been through the evolution of environmental compliance, waste minimization, recycling and water conservation. This outstanding job has earned Able a Certificate of Commendation from the Metropolitan Water Reclamation District of Greater Chicago.