Investigation of the Role of Passivity in Stress Corrosion Cracking of Duplex Stainless Steels;Research rept

摘要

Electrochemical and surface analytical investigations have been carried out to elucidate the behavior of duplex stainless steels in chloride environments which can cause stress corrosion cracking. Comparisons have been made between S32304 (23Cr 4.6Ni 0.12N) S31803 (22Cr5.5Ni 3Mo 0.16N) and S32750 (25Cr7Ni 3.8Mo 0.26N) in 8Mo and 12M chlorides (LiCl, CaCl(sub 2) and MgCl(sub 2)) at 100 degrees C and 120 degrees C. Polarization curves have been obtained for the various alloy-environment combinations, scratch experiments have been conducted to investigate the depassivation-repassivation behavior and analysis of the surface films has been performed with glow discharge optical emission spectroscopy (GDOES).