Analysis of the intergranular corrosion susceptibility in stainless steel by means of potentiostatic reactivation tests

Abstract: Intergranular corrosion cracking in stainless steels is a selective corrosion attack due to a local (grain boundary) Cr depletion. An undesired Cr carbides (Cr 23 C 6 ) precipitation after heat treatment in the sensitization temperature range (usually between 550 and 850°C, depending on the steel chemical composition) is obtained with a kinetics that is mainly influenced by the C content. In this work, the sensitization susceptibility of four sensitized stainless steels was investigated by means of potentiostatic reactivations tests. In addition, chronoamperometric tests and scanning electron microscope (SEM) observations of the specimens surfaces were performed in order to analyze the evolution of the corrosion morphologies.