Effect of Alloying Elements on Electrochemical Behavior of Fe-18Cr Alloy

摘要

The present work reports electrochemical behavior of Fe-18Cr alloy thin films with various alloying elements prepared by ion beam sputtering technique. Polarization curves measured in H_2SO_4 solution reveal that active dissolution is effectively suppressed by the addition of Mo, Cu, Ni, Nb or Ti whereas the addition of Al, Si or Mn do not affect the active dissolution. Except for Zr, Al and Si, most of alloying elements suppress pitting corrosion in severe chloride solution. In particular, Nb is very effective and the small amount of Nb completely inhibits pitting corrosion. Reactivation behavior of passive films on Fe-18Cr alloys in H_2SO_4 solution is strongly affected by alloying elements. Nb, Mo, Ti and Ni shift the reactivation potential in less noble direction, meaning that they stabilize passivity of Fe-18Cr. On the other hand, Mn and Si deteriorate the passivity.