Welding And Passivation of Stainless Steels

A “Steel” should contain at least 10,5 % Chromium in order to be called “Stainless Steel”.
At this  chromium level,  a chromium enriched  surface oxide,  forms a film and this film keeps the Steel from “rusting”. This film layer should be protected to keep rustness and  whenever it is destroyed, it can be seld-repaired but air contact should not be prevented. If this film layer is removed deliberately by welding, cutting etc., a help is required for reformation of chromium oxide which is called “passivation”.