Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5439966 | Corrosion Science | 2017 | 12 Pages |
â¢Corrosion domains are established for 410 SS as a function of [HCl] and temperature.â¢Synergistic effect of hydrogen and chloride ions is found for passive film breakdown.â¢Permanent uniform degradation of passive film occurs above critical temperature.â¢Metastable pitting initiates from non-metallic inclusions below critical temperature.â¢Sigma phase particles are identified in 410 SS by TEM/SAED and remain uncorroded.
The corrosion behavior of AISI 410 stainless steel was investigated in relatively dilute HCl solutions with different concentrations and temperature levels. General corrosion occurred at pH < 1.5 while pitting occurred at 2.25 â¤Â pH â¤Â 4.25. Important pitting parameters were evaluated as a function of both temperature and HCl concentration. Critical temperature (Tcrit) increased linearly with pH. Below Tcrit, passive film remained largely intact and sporadic metastable pitting initiated from non-metallic inclusions. Above Tcrit, passivity was completely destroyed and black film consisting of oxy-hydroxide and hydrated oxide formed. Sigma-phase particles were found in this steel and remained un-corroded.