Rainbow Colors in Stainless Steel Welding

Are they good or bad?

Different joints will have different levels of admixture (the mixing of weld metal with base metal) . The higher the admixture the more silicon islands will form on the surface of the weld.

We receive several calls about welding stainless and the beautiful rainbow colors, or lack thereof, on the weld and heat affected zone.  Is the tinting an indication of quality?  Are these colors acceptable? Do they show that the weld had enough heat to penetrate?  Why do they need to be cleaned?  The questions are endless. […]