Benefits of Electropolishing

Electropolishing enhances the corrosion resistance, luster and smoothness of many metals, particularly the 300 series stainless steels. Equally good results may be obtained on the 400 and precipitation hardening series, inconel, hastelloy and other nickel-based alloys.

• Corrosion Resistance:  Often known as "super-passivation," electropolishing  effectively removes impurities leaving a  homogenous metal surface.  Furthermore, a high chrome-iron oxide ration can be achieved which is of particular importance in UHP applications as discussed in a separate section. As a result, the inherent corrosion-resistance of such alloys as stainless steel is greatly improved. Salt spray tests have proved that electropolished parts are four to five times more resistant to corrosion than untreated parts.

• Microfinish:  The normal electropolishing process improves the microfinish by a factor of 2, i.e. 50 Ra is reduced to 25 Ra. With special processing, this can be reduced even further. The smoothness obtainable has a number of applications:  where antifriction and non-galling are requirements such as in the production of gears and valves; where release properties are needed inside vessels or tubes; or where heat and light reflectivity is a factor.

• Appearance:  A widespread use of electropolishing is for enhancement in the appearance of a product. No other finish can provide such a brilliant effect, and imperfections such as stains, heat discoloration, weld marks and minor scratches are eliminated or minimized.

• Preparation of Surfaces:  As a pre-treatment for further processing, such as welding, plating or anodizing, electropolishing is used to remove the contaminated surface generated during manufacturing, leaving a smooth, chemically clean surface with superior adhesion qualities.

• Deburring:  Some parts are too heavy or fragile for tumbling, or have intricate shapes and deep recesses that are difficult to deburr mechanically.  Electropolishing is the best answer to such deburring problems, and is usually less expensive than other methods.

• Cleanliness:  Electropolished surfaces are stain and bacteria resistant to meet the exacting cleanliness standards of the food-processing, medical equipment and chemical industries.

• Endurance:  Cracks and other surface defects act as stress-concentration sites, and when removed by electropolishing the fatigue strength of a metal is improved. This applies particularly to springs, where tests have shown fatigue life to be greatly increased after treatment.