Stainless Steel Electropolishing Service

Stainless steel electropolishing (or stainless steel polishing) could be described as a “reverse plating” process. It uses a combination of rectified electrical current and a blended chemical electrolyte bath to remove imperfections from the surface of a stainless steel part and create a clean, bright surface.

How Does Electropolishing Work?

In stainless steel electropolishing, impurities, imperfections, and burrs are removed, ion by ion, from the surface of the metal object being processed. Electropolishing is an effective replacement for more traditional mechanical finishing techniques such as grinding, buffing, milling and blasting.

To start the stainless steel polishing process, parts are submerged in a temperature-controlled electrolyte bath and connected to positive DC voltage. The parts act as electrical anodes (or positive terminals), while cathodes (negative terminals) inside the tank draw current from the parts through the conductive electrolyte liquid. As the current travels from the parts to the cathodes, it draws metal ions from the surface of the parts through the electrolyte.

Stainless steel’s natural corrosion resistance is provided by a chromium oxide film on its surface. This film is thickest over micro depressions, and thinnest over micro projections, such as burrs; electrical resistance is at its weakest where the film is thinnest, which results in an increased rate of metallic dissolution during electropolishing. Material from the entire surface of the part is removed in this process, but burrs and other projections are more rapidly removed, leveling and smoothing the surface.

After processing, electropolished parts will have a clean and polished surface with a uniform luster. There are none of the fine directional lines associated with abrasive polishing.

Electrolyte Solutions

The electrolyte solutions used for stainless steel electropolishing most often consist of high viscosity acid solutions, such as sulfuric or phosphoric acid mixtures. Arrow Cryogenics carefully formulates and maintains our electrolyte chemistries to ensure the best and most effective results for your stainless steel polishing project.

A Safe Alternative to Chrome Plating

Stainless steel electropolishing is very similar to high polish chrome plating but uses none of the harmful chemicals required for chrome plating. Electropolishing is a far safer and more environmentally-friendly process. 

Electropolishing vs. Passivation

Electropolishing is a more aggressive alternative to stainless steel passivation, providing longer-lasting benefits and as much as 30 times greater corrosion resistance.

Passivation improves treated parts’ corrosion resistance, removes foreign particulates, and leaves surfaces clean, but does not change the parts’ aesthetics. Electropolishing strips away contaminants, smooths out surface imperfections, and leaves parts visibly bright and shiny; parts retain these characteristics even in harsh or highly corrosive environments. Stainless steel electropolishing also provides numerous other benefits, listed below.

Benefits of Arrow Cryogenics’ Stainless Steel Polishing Process

Customers rely on Arrow Cryogenics’ expertise in stainless steel electropolishing to finish their complex stainless steel parts and components. Electropolishing:

  • Polishes areas inaccessible by other polishing methods
  • Improves surface reflectivity and brightness
  • Improves the surface finish by leveling micro peaks and valleys
  • Removes iron from the surface and enhances the chromium/nickel content, providing the best method of passivation for stainless steel
  • Removes a small amount of material (roughly 20-40 micrometers thick) from the part surface, taking small burrs and high spots with it
  • Can be used to slightly reduce the size of parts, if necessary
  • Provides a clean and smooth surface that is easier to sterilize
  • Provides a corrosion resistant surface
  • Removes surface discoloration caused by heat treating and/or oxidation
  • Creates a bright, reflective finish 

To ensure consistency and quality, we perform all stainless steel electropolishing, stainless steel passivation, and quality control operations to the highest standards required by the semiconductor, aerospace, and medical industries. Arrow Cryogenics is ISO 9001:2015 and Nadcap certified for chemical processing.

Contact Us for Stainless Steel Electropolishing

Request a quote on stainless steel polishing for your parts. Contact Arrow Cryogenics to learn more. Complimentary sample processing is available upon request.