Potentiodynamic polarization parameters for mild steel corrosion in 20% formic acid in the presence and absence of different concentrations of 8b and 2 mmol KI.
| Conc. (ppm) | KI (mmol) | PDP | LPR | |||||
|---|---|---|---|---|---|---|---|---|
| E corr (mV) | β a (mV dec−1) | −βc (mV dec−1) | I corr (μA cm−2) | η PDP (%) | R p (Ωcm2) | η LPR (%) | ||
| Blank | — | −488.6 | 408.6 | 531.4 | 723.3 | — | 142.8 | — |
| 1 | — | −455.6 | 203.9 | 418.5 | 318.5 | 56.0 | 311.2 | 54.1 |
| 1 | 2 | −449.6 | 115.1 | 237.0 | 46.67 | 93.6 | 1645 | 91.3 |
| 5 | — | −455.6 | 210.4 | 408.8 | 284.2 | 60.7 | 358.7 | 60.3 |
| 5 | 2 | −397.0 | 319.7 | 231.2 | 15.46 | 97.9 | 4127 | 96.5 |
| 10 | — | −458.6 | 197.5 | 337.6 | 248.3 | 65.7 | 376.9 | 62.1 |
| 10 | 2 | −321.8 | 313.0 | 207.5 | 14.38 | 98.0 | 4791 | 97.0 |
| 20 | — | −458.6 | 190.3 | 375.3 | 235.7 | 67.4 | 419.8 | 66.0 |
| 20 | 2 | −266.2 | 323.4 | 198.0 | 13.48 | 98.1 | 6550 | 97.8 |
| 50 | — | −458.6 | 193.9 | 372.0 | 207.7 | 71.3 | 482.9 | 70.4 |
| 50 | 2 | −209.0 | 243.0 | 170.9 | 6.813 | 99.1 | 9037 | 98.4 |
| 100 | — | −461.7 | 245.8 | 440.9 | 131.8 | 81.8 | 701.0 | 79.6 |
| 100 | 2 | −324.8 | 181.0 | 156.6 | 7.057 | 99.0 | 9272 | 98.8 |