Electrochemical behaviour and surface analytical of welded stainless steel in the room temperature simulated PWR water

Abstract

In this study, the electrochemical behaviour of different parts of welded AISI 304L stainless steel in the simulated Pressurized Water Reactor (PWR) water at room temperature (25 deg.C) was studied by the different electrochemical techniques such as the potentiodynamic polarization measurements and electrochemical impedance spectroscopy, and the compositions of the passive film formed on the surface were investigated by XPS. In addition, the surface images of samples after electrochemical tests were also carried out by SEM. The results indicated that the heat affected zone has the worst corrosion behaviour. The heat affected zone has more pits than the other parts, which may lead to reducing corrosion resistance. In addition, the passive film of different zones of the welded stainless steel has the different chemical compositions. The Cr element on the fusion zone and heat affected zone are mainly the Cr (met), Cr2O3, and Cr (OH)3.while on the base metal surface is the Cr(met), Cr2O3,Cr (OH)3 and CrO3. © 2012 ISIJ.