Effects of Na3PW12O40 on the corrosion behavior of carbon steel in 55 %LiBr solution

✍ Scribed by C.H. Liang; X.Q. Hu; L. Ma

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: German
• Weight: 221 KB
• Volume: 58
• Category: Article
• ISSN: 0947-5117
• DOI: 10.1002/maco.200603981

✦ Synopsis

Electrochemical technologies, chemical immersion tests and surface detection technologies were adopted to study the inhibition performance of Na 3 PW 12 O 40 inhibitor on carbon steel in 55 % LiBr þ 0.07 mol/L LiOH solution, and the inhibition mechanism was discussed. Results indicated that Na 3 PW 12 O 40 inhibitor caused the decrease of both anodic and cathodic polarization current density and a widening of the passive potential region. It behaved as a mixed inhibitor. When the concentration of Na 3 PW 12 O 40 in 55 % LiBr þ 0.07 mol/L LiOH solution was 300 mg/L, excellent inhibition performance on carbon steel was obtained. When the solution temperature were 145 C, 160 C, 180 C and 200 C, respectively, the corrosion rates of carbon steel were 13.07 lm/y, 17.74 lm/y, 24.55 lm/y and 73.52 lm/y accordingly. Na 3 PW 12 O 40 inhibitor exhibited an excellent inhibition performance at high temperature. Na 3 PW 12 O 40 is a strong oxidant. Fe was oxidized to Fe 2 O 3 and itself was deoxidized to heteropoly blue. By this mechanism, an integrate compact passive film mainly comprising Fe 2 O 3 may be formed on the carbon steel surface, and the corrosion of carbon steel in 55 % LiBr solution may be retarded by this passive film.