The Influences of Alloying on the Passive Behaviour of Steels in a Bicarbonate Medium Studied by Electrochemistry and XPS

摘要

Passive films formed in 0.5 M NaHCO_3 and 0.5 M NaHCO_3+0.01 M KCl aqueous solution on carbon steel, chromium steel and high speed steel have been characterized by electrochemistry and XPS. The influence of heat treatment on the passive film properties of chromium steel and HSS was also studied. Polarisation curves show that the steel composition influences the onset of passive film formation. Chromium and high speed steels show a higher ability to passivate as a results of the higher alloying content, corroborated by open circuit potential measurements.