Citric Acid Passivation Process

As an industry authority, it’s our goal to provide our customers with easy access to information about the extensive range of services we provide. Some of the more technical processes we use to finish parts can be complicated to explain; that’s why we think it’s valuable to offer an inside look at the details of our techniques and innovative services. The citric acid passivation process is one of our most commonly requested services due to its effectiveness and consistent results.

What is Citric Acid Passivation?

Passivation as a general term is the technique used for Imparting metal with some sort of protective layer. The goal of passivation is to protect the metal from corrosion, and there are many different ways to passivate metal. Citric acid passivation uses concentrated citric acid to passivate metals like stainless steel and titanium. The concentrated citric acid works to pull iron from the surface, then forms a protective layer on the outside of the part like a protective shell.

The citric acid passivation process is often confused with another finishing process called pickling, but they are not the same. The process of acid passivation begins by creating a citric acid solution with citric acid and water, making sure the liquid is uniform. A uniform solution is integral to an evenly passivated finish. The acid solution is then heated and the parts to be passivated are added to the solution and fully submerged for an amount of time that’s decided by the desired finish.

Citric Acid Passivation Applications

The method of citric acid passivation is most commonly employed when parts require some higher level of corrosion resistance. Parts of all sizes can benefit from the layer of oxidation produced by citric acid passivation, but the material of the parts dictates how well the passivation will work. While stainless steel parts are the most commonly passivated using citric acid, other metals like titanium can benefit equally. Industries who use passivated parts vary from automotive and aerospace to medical, food and beverage processing, defense and most commonly chemical and wastewater treatment, where corrosive environments are most common.

Our Passivation Protocol

At RP Abrasives, we offer multiple citric acid passivation options depending on the needs of our customer. We can passivate a wide range of part sizes, including batches of small parts and individual larger parts. We formulate our citric acid solution using concentrated citric acid and deionized water, ensuring the best quality and consistently excellent results. Before we begin the passivation process, we thoroughly clean each part, ensuring all surfaces passivate evenly. Once we have completed the citric acid passivation process we complete a copper sulfate test which analyzes the effectiveness of the passivation against corrosive conditions.

For more information about citric acid passivation or our other services, contact us today.