Electron Microprobe Study of Cl − -Agglomeration at Sulphide Inclusions in Iron and Stainless Steel

Abstract

An electron microprobe analyser was used to study the surface of iron and stainless steel after anodic polarisation in Cl⁻-containing borate buffer solutions. Distinct, discrete areas of strongly localised accumulation of chlorides were observed on the metal surface after polarisation at potentials lower than the potential of pit nucleation. These areas occurred mainly at the boundaries between non-metallic inclusions and the metal matrix.