passivation of stainless steel citric acid

pipes showing passivation of stainless steel

Using Chem-Crest® ProPass Citric Acid Solution and Crest Ultrasonics Cleaning Systems

Also be sure to see our
recommended equipment for ultrasonic stainless steel passivation.

Chem-Crest ProPass is a passivation and oxidation removal concentrate. It is used for the passivation of various grades of stainless steel. ProPass can also remove various levels of rust and oxidation from different types of steel and deoxidize various metals, including brass and aluminum.

Our phosphate-free citric passivation concentrate and deoxidizer cleaner is designed to remove surface contamination, increase corrosion resistance, and remove discoloration, tarnishes, scales, and oxides. It is an alternative for nitric acid passivation, and passes citric acid passivation evaluations such as ASTM A967. Please contact your local Crest Ultrasonics representative for further information.

Chem-Crest ProPass is compatible with stainless steel, brass, bronze, copper, zinc, and aluminum. It is safe to use on glass, ceramics, and plastics. For ferrous (non-stainless steel) surfaces, you must protect them immediately after ProPass treatment with an appropriate rust inhibitor.

What Makes Our Passivation of Stainless Steel Solution Different?

Price. Delivery. Effectiveness. It’s really that simple.

Chem-Crest ProPass is priced lower than our primary competitor, and we offer fast shipping on orders, in gallon, case, pail, drum, or tote sizes.

Our clients for ultrasonic stainless steel passivation are represented in many industry sectors, including aerospace, medical, dental, and industrial. Please contact your local Crest Ultrasonics representative for application-specific questions, and to learn how Chem-Crest ProPass can further optimize your cleaning and passivation needs.

How Does Stainless Steel Passivation Work?

All grades of stainless steel form a thin, nonreactive film of chromium oxides. These create a protective barrier to prevent surface erosion. When manufacturers produce stainless steel products, free iron can be deposited on the surface. This free iron oxidizes easily, forming rust on the product’s surface even though we still call it “stainless steel.”

Passivation of stainless steel with ProPass Citric Acid Solution removes free iron and other surface contaminants from the stainless steel, while simultaneously promoting a passive chromium/nickel oxide layer to act as a future barrier to corrosion.

So the passivation of stainless steel is a metal finishing process, using citric acid to remove free iron from an object’s surface. You create a chemical barrier against rust, extend product life, remove surface contaminants, and reduce the need to maintain stainless steel products.

Using Ultrasonics to Improve Passivation of Stainless Steel

To reach all exterior and interior surfaces of complex parts, an ultrasonic bath is ideal for the passivation of steel. Items are placed into a metal basket, which is lowered into a Crest Ultrasonics bath, and then precision cleaned using cavitation (think “imploding miniature bubbles”) to lift debris. The basket is then rinsed and lowered into a bath of ProPass Citric Acid Solution, then rinsed and dried.

A typical ProPass Citric Passivation clean line will use the following recipe, which can be offered for use with our Digital Modular Series (DMS) ultrasonic cleaning equipment (other Crest ultrasonic cleaning equipment can be used):

passivation of stainless steel suggest workflowUsing Crest Ultrasonics automated ultrasonic passivation equipment combines cleaning, rinsing, passivation, rinsing, and drying within one working system — freeing your operators to complete other tasks and reducing your overall cleaning costs.

Chem-Crest ProPassChem-Crest ProPass is a phosphate-free citric passivation concentrate and deoxidizer cleaner designed to remove surface contamination, increase corrosion resistance, remove discoloration, tarnishes, scales and oxides. Learn more

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