Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
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Flow-Accelerated Corrosion Behavior of SA106 Gr.C Steel in Alkaline Solution Characterized by Rotating Cylinder Electrode

  • Kim, Jun-Hwan (Korea Advanced Institute of Science and Technology) ;
  • Kim, In-Sup (Korea Advanced Institute of Science and Technology)
  • Published : 2000.12.01
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Abstract

Flow-Accelerated Corrosion Behavior of SA106 Gr.C steel in room temperature alkaline solution simulating the CANDU primary water condition was studied using Rotating Cylinder Electrode. Systems of RCE were set up and electrochemical parameters were applied at various rotating speeds. Corrosion current density decreased up to pH 10.4 then it increased rapidly at higher pH. This is due to the increasing tendency of cathodic and anodic exchange half-cell current. Corrosion potential shifted slightly upward with rotating velocity. Passive film was formed from pH 9.8 by the mechanism of step oxidation and the subsequent precipitation of ferrous species into hydroxyl compound. Above pH 10.4, the film formation process was active and the film became stable. Corrosion current density showed increment in pH 6.98 with the rotating velocity, while it soon saturated from 1000 rpm above pH 9.8. This seems that activation process which represents formation of passive film on the bare metal surface controls the entire corrosion process

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