Effect of yttrium on the corrosion behavior of 09CrCuSb alloy in NaCl solution

• The presence of alloyed yttrium inhibits the pitting corrosion of in NaCl solution.
• Corrosion product film with yttrium addition blocks up the diffusion of Cl−.
• Yttrium addition increases the electrochemical reaction resistance of 09CrCuSb alloy.

The effect of yttrium on the corrosion behavior of 09CrCuSb alloy in 3.5 wt.% NaCl solution has been investigated. The results demonstrate that addition of 0.15 wt.% Y effectively improves the pitting corrosion resistance of such alloy. Yttrium addition inhibits the precipitation of MnS, restrains the initiation of pitting corrosion. Moreover, the corrosion product film with yttrium addition blocks up the diffusion of Cl− to the matrix effectively which improves the resistance of pitting corrosion greatly. The electrochemical test exhibits a decrease passive current as well as a higher resistance of the Y-modified alloy.