Passivation of stainless steel
Passivation at a glance
Passivation of stainless steel - surface treatment for a long service life of your components.
Stainless steel is ubiquitous and is used in many areas. Whether in mechanical engineering, the food industry or the pharmaceutical sector - the material offers outstanding properties. It is durable, resilient and less susceptible to the accumulation of dirt. However, in order to protect it completely against corrosion (rust formation), it is often necessaryto passivate stainless steel beforehand .
At plasmotion, we specialize in finishing by plasma polishing. We use state-of-the-art technologies to carry out precise and high-quality surface treatment.
Your expert for questions
- Sven Friedemann
- Technical sales
- Phone +49 3731 37736 - 31
Why passivate?
Stainless? Depending on the application, stainless steels can also corrode.
The reason for the corrosion resistance for which stainless steels are known lies in the passive layer that completely covers the component. This consists largely of chromium oxide (Cr2O3) and is formed naturally by reaction with atmospheric oxygen. In the application, it forms a non-reactive barrier between the base material and the environment. The result: no visible corrosion attack. Although this passive layer is microscopically thin, it still takes several days to weeks to fully form. During this time, the base material can react with air pollutants. The result: residual iron components and mixed iron crystals as nuclei for a subsequent corrosion attack. To prevent this, the passive layer is further expanded or modified by a chemical process - passivation.
What is passivation?
The optimization of the passive layer provides effective protection against corrosion attacks.
If the components are exposed to a particularly aggressive medium, such as in boatbuilding or fluid technology, corrosion can occur even with stainless steel. It has been known for more than 60 years that stainless steel is only truly corrosion-resistant if it has been polished and passivated. For the latter, the corresponding stainless steel strips, semi-finished products or components are immersed in a bath and chemically treated. In the reaction with the bath chemistry, usually nitric acid or citric acid, residual iron is removed from the passive layer, which is further expanded and in some cases structurally optimized. The result: a dense passive layer and a stainless steel component with long-term durability.
Areas of application for passivation
In many areas of application, stainless steel surfaces with passivation are mandatory in order to meet the necessary standards.
Passivation of stainless steel is used for surgical instruments, medical devices and implants - making them corrosion-resistant and reliably biocompatible.
In chemical plant engineering, elements and components that are exposed to aggressive chemical influences are passivated. This includes containers, pipelines and equipment.
In the pharmaceutical industry in particular, absolute passivity of components that come into contact with the product is crucial. This includes various systems, components and equipment, which therefore have optimized properties after stainless steel pickling and passivation.
To meet hygiene standards in production, systems, equipment and pipelines are passivated.
Components and cladding made of stainless steel - for example in refrigerators or dishwashers - are passivated.
Vehicle components that are exposed to various weather conditions and need to be protected against corrosion are also passivated.
Components in aircraft and spacecraft, which are exposed to high loads and must be corrosion-resistant, must also undergo this process.
Here, systems and components are often exposed to high temperatures and aggressive environments and must be protected. In this respect, passivation is standard.
Systems and components used in water distribution and treatment that may corrode must be passivated. This also applies to systems and components for air pollution control.
Various parts and components such as housings and brackets in electronic devices are passivated here.
Advantages of passivated surfaces
Thanks to an optimized passive layer, the stainless steel is and remains protected against corrosion.
After passivation, the chromium oxide layer is closed and free of residual iron. This means there are no possible germs for corrosion. This leads to a longer service life for stainless steel components and parts. The result: low operating and maintenance costs.
A passive layer also has hygienic properties. Impurities and the adhesion of bacteria (contamination) are minimized.
If an aesthetic appearance is desired, a passive layer keeps stainless steel looking attractive for longer.
The surface can also withstand greater loads and aggressive environments. These include chemical and maritime environments, as well as higher ambient temperatures.
If stainless steel is to be further processed, a passive layer favors such measures thanks to better processing properties
Are you looking for an efficient and environmentally friendly pre-process for passivation?
Plasma polishing
Only polished and passivated stainless steel is truly durable. We have the solution.
In addition to the targeted build-up or modification of the passive layer, it is crucial for the long, safe use of stainless steel parts that roughness peaks are specifically removed. The aim is a clean, smoothed and passivated surface.
Today, this step is often carried out using electropolishing. More and more industrial companies are also turning to the more efficient and sustainable alternative - plasma polishing from plasmotion. Thanks to the unique combination of plasma physics and electrochemistry, stainless steel components can be polished more quickly. The properties achieved are impressive thanks to superior roughness and unrivaled shine - without any significant thermal or mechanical influences.
We will of course be happy to advise you on the potential of plasma polishing for your application. Talk to our experts!
plasmotion is the only solution provider to offer the full spectrum of plasma-electrolytic surface finishing: classically in the electrolyte bath and selectively with the electrolyte jet. Do you need support with polishing stainless steel components or are you facing a difficult challenge? We will be happy to look at your request and your situation together to find a suitable solution. With our globally unique technology portfolio, we can meet (almost) any specific surface challenge.
Plasma polishing
Do you value quality, efficiency and reliability? Then our plasma polishing could be the right solution for your application. When your workpiece is immersed in our special electrolytes, they boil on the surface when a DC voltage is applied and form a contour-true vapor film. This results in the unique plasma-electrolytic removal of burrs and micro-roughness, with simultaneous component cleaning.
JETPEP: Jet plasma polishing
With JETPEP, plasmotion has succeeded in innovating: the plasma-electrolytic removal is achieved in a single jet and can therefore be applied to the exact surface. This technology can be used not only for surface finishing by polishing, but also for targeted deburring, especially of complex components. Reliable adjustment of roughness and gloss on stainless steel components as well as the finishing of weld seams can also be fully automated - whether with robots, axis kinematics or multi-nozzle clusters.
Services from plasmotion
Plasma polishing can be seamlessly integrated into your production.
You can use our unique active principle for more than just contract manufacturing. With our customized system solutions, you have access to a technology that not only enables greater efficiency, but also greater sustainability through the use of aqueous salt solutions. Replace electropolishing with plasma polishing and benefit from previously unattainable surfaces - we will be happy to advise you!
Your next steps
Make your production future-proof - with plasma polishing solutions from plasmotion.
Your challenge - our solution. Your direct route to a customized offer.
Let's talk about your specific concerns.
We would be happy to convince you of the strengths and possibilities of our technologies based on your components. The first step is a sampling. Simply get in touch with us.
Do you have questions about our technologies and applications?
Do your materials and surfaces have special requirements? Are you unsure whether plasma polishing is right for your product? Would you like to know how plasmotion can help you as a solution provider? I will be happy to answer your questions personally.
Your expert for questions
- Sven Friedemann
- Technical sales
- Phone +49 3731 37736 - 31