Investigation of the Active Dissolution Behaviour of a 22% Chromium Duplex Stainless Steel with Small Ruthenium Additions in Sulphuric Acid

Abstract

The dissolution behaviour of a 22% chromium duplex stainless steel with very low nitrogen content and containing various amounts of ruthenium was investigated. It was found that the ruthenium additions inhibits the anodic dissolution behaviour when active corrosion took place. Furthermore it was established that only the ferrite phase corrodes preferentially at various potentials in the active and passive regions, which is contrary to the behaviour of similar commercial duplex stainless steels with significant nitrogen contents, and which do not contain ruthenium.