Stainless Steels Are Iron Based Alloys Containing At Least 10.5% Chromium. They Achieve Their Stainless Characteristics Through The Formation Of An Invisible And Adherent Chromium Rich Oxide Film. Alloy 347 Is A General Purpose Austenitic Stainless Steel With A Face Centered Cubic Structure. It Is Essentially Non-magnetic In The Annealed Condition And Can Only Be Hardened By Cold Working. Niobium Has Been Added To Suppress Grain Boundary Chromium Carbide Precipitation.