We’re often asked if electropolishing removes the “heat tint” left on stainless steel fabrications due to welding.
Will the electropolishing process clean welds?
The answer is no. To help remove the heat tint or discoloration associated with welding, we subject parts to a descaling cycle (often called “pickling”) in order to loosen up and remove the heat scale.
We then electropolish (EP) the parts, which improves the surface finish, including the weld joint, and gives parts a chrome-like appearance and finish without the high costs and environmental disadvantages of chrome plating.
Can we passivate our welded parts without electropolishing?
Yes, you can. As part of the EP process, parts are naturally passivated, meaning the free iron, which promotes aggressive corrosion, is removed. However, passivation can be accomplished without EP.
To passivate, welded parts are cleaned and the heat tint, oils, dirt, etc. are removed. Parts are then subject to a Nitric Acid bath, which adds a passive layer to the parts but doesn’t change the surface finish. This means the now passivated parts look the same coming out of the bath as they did going in.
What are the benefits of electropolishing welded stainless steel parts?
Electropolishing offers a number of benefits including:
- Removes elemental or free iron from the surface – dramatically improving resistance to corrosion.
- Removes stressed or disturbed layers of surface metal caused by welding, cutting, or mechanical finishing.
- Provides the most superior form of passivation.
To learn more about passivation, see our Electropolishing FAQs.