Stainless Steel Electropolishing Service
Stainless Steel Electropolishing for Metal Parts
Stainless steel electropolishing is a “reverse plating” process that utilizes a combination of rectified electrical current and a blended chemical electrolyte bath to remove imperfections from the surface of a stainless steel part, which creates a cleaner, brighter surface. Electropolishing is also referred to as electrochemical polishing, anodic polishing or electrolytic polishing and it can be used to polish, passivate, and deburr stainless steel parts.
The Stainless Steel Electropolishing Process
The stainless steel electropolishing process begins by submerging the parts being treated in a temperature-controlled electrolyte bath that is connected to a positive DC voltage charge. The parts within the bath 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. Throughout this process, the part surface area metal is dissolved in the electrolyte. This process can be tightly controlled to dissolve extremely small amounts of the parts surface area resulting in the capabilities micron level thickness of part surface area.
Stainless steel’s natural corrosion resistant chromium oxide surface 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 through direct leveling and smoothing of the surface.
Stainless steel electropolishing removes impurities, imperfections, and burrs from the surface of the metal objects being processed. Electropolishing is an effective replacement for more traditional mechanical finishing techniques such as grinding, buffing, milling and blasting. After processing, electropolished parts maintain a clean and polished surface with a uniform luster, without the fine directional lines associated with abrasive polishing.
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.