The influence of phosphate on repassivation of 304 stainless steel in neutral chloride solution

Repassivation behavior of 316L stainless steel in borate buffer solution: Kinetics analysis of anodic dissolution and film formation

“…2, the current density decreases very fast within the initial 10-10 2 ms, then decay rate gradually slows down. The similar results were also reported in other studies [15][16][17]29]. Because of the low conductivity of the borate buffer solution, un-compensated solution resistance needs to be taken into account during electrochemical experiments.…”

Electrochemical, SEM and XPS investigations on phosphoric acid treated surgical grade type 316L SS for biomedical applications

“…Here, this result can also be explained by the adsorption of phosphate ions on the surface. Lakatos-Varsányi et al [19] have also reported the formation of CrPO 4 Á 2H 2 O and Fe-Cr hydroxide during exposure of stainless steels to phosphate containing solution. Our results are in good agreement with their results.…”

“…6 k, l. The phosphorus 2p spectrum of acid treated surface exhibited a singlet at 133.8 eV corresponding to 2p 3/2 of phosphate (PO 4 3-) species [19]. However, the P 2p spectrum of untreated specimen did not show a peak in the P 2p region and indicates the absence of PO 4 3-.…”

“…The amount of phosphate on the surface is considerably high. The study conducted by Lakatos-Varsányi et al [19] suggested that phosphate does not influence the electrochemical parameters such as dissolution current in the active range, the passive current and the pitting potential. However, they further argued that phosphate enhances the repassivation potential by forming chromium phosphate on the surface of the pit walls.…”

“…In the present study, the repassivation obtained with scanning the potential in the cathodic direction is found to be lower when 316L SS is treated with H 3 PO 4 compared to untreated 316L SS. It could be argued that the high repassivation of the pits in the H 3 PO 4 -treated 316L SS is due to the formation of a phosphate layer on the surface of the pit walls as Cr-phosphates [19].…”