Best practise in stainless steel fabrication includes maintaining or restoring clean metallic surfaces. When discolouration is observed, for instance, on edges, in welds or in the heat-affected zone, it should always be removed.
Heat tint is not merely an aesthetic question: the oxides, which are visible as discolorations, do not have the protective and self-repairing properties that the original passive layer has. It should therefore be removed even from non-visible parts of a fabrication. Ferrous contamination can be another point of concern. When dust from the cutting, grinding or welding of carbon steel deposits on stainless steel, it corrodes quickly and forms unsightly rusty spots. Where such ferrous contamination has occurred, appropriate surface treatment is strongly recommended.
Photo courtesy of Euro Inox
Euro Inox devoted a concise new brochure to the most frequently asked questions about post-fabrication surface treatment and explains the relevant techniques. An annex indicates the compositions of common chemicals and lists standard parameters for their use. A literature list refers to standards and other sources of further information. The eleven-page paper can be downloaded from the Euro Inox website.
