Effect of electrolyte composition on the electrochemical potentiokinetic reactivation behavior of Alloy 600

The effects of electrolyte composition and concentration on the reactivatio n behavior of Alloy 600 in H2SO4 + KSCN solution were investigated by condu cting single-loop electrochemical potentiokinetic reactivation (SL-EPR) tes ts. The experimental results revealed that two anodic peaks existed, which corresponded to pitting corrosion and matrix corrosion, respectively, in th e reactivation polarization curve of non-sensitized Alloy 600. Alternately, for sensitized Alloy 600, an additional peak associated with grain boundar y corrosion appeared in the potential range of +60 to -10 mV(SCE) within th e reactivation polarization curve. The shape and current density of the rea ctivation curve of Alloy 600 with different degrees of sensitization varied with the electrolyte composition adjustments. A maximum peak anodic curren t density associated with grain boundary corrosion occurred when the concen tration ratio of H2SO4/KSCN was 10 for the sensitized low carbon Alloy 600. (C) 2001 Elsevier Science B.V. All rights reserved.