Research Article
Corrosion Inhibition Effect of 4-Hydroxy-N′-[(E)-(1H-indole-2-ylmethylidene)] Benzohydrazide on Mild Steel in Hydrochloric Acid Solution
Table 3
Electrochemical impedance parameters for the corrosion of mild steel in 1 M HCl in the absence and presence of inhibitor at different temperatures.
| Temp. (°C) | Conc. of HIBH (mM) | (Ω cm2) | (μF cm−2) | | % IE |
| 30 | 0 | 15.70 | 1785 | 0.705 | — | 0.1 | 89.55 | 84.31 | 0.732 | 82.5 | 0.2 | 96.64 | 67.50 | 0.753 | 83.7 | 0.4 | 101.5 | 64.19 | 0.757 | 84.5 | 0.6 | 115.1 | 54.61 | 0.763 | 86.3 | 0.8 | 122.0 | 50.58 | 0.766 | 87.1 |
| 40 | 0 | 9.63 | 3761 | 0.765 | — | 0.1 | 60.07 | 207.4 | 0.767 | 83.9 | 0.2 | 62.10 | 166.3 | 0.778 | 84.5 | 0.4 | 66.39 | 141.2 | 0.795 | 85.4 | 0.6 | 71.74 | 121.3 | 0.799 | 86.5 | 0.8 | 76.35 | 94.24 | 0.817 | 87.3 |
| 50 | 0 | 5.00 | 12936 | 0.773 | — | 0.1 | 31.99 | 540.4 | 0.768 | 84.3 | 0.2 | 33.75 | 450.1 | 0.778 | 85.1 | 0.4 | 36.35 | 401.1 | 0.788 | 86.2 | 0.6 | 40.47 | 350.3 | 0.795 | 87.6 | 0.8 | 42.5 | 289.8 | 0.82 | 88.2 |
| 60 | 0 | 1.90 | 55870 | 0.742 | — | 0.1 | 13.41 | 2333.8 | 0.756 | 85.8 | 0.2 | 13.81 | 2158.4 | 0.762 | 86.2 | 0.4 | 14.86 | 1945.8 | 0.794 | 87.2 | 0.6 | 15.90 | 1709.0 | 0.807 | 88.0 | 0.8 | 18.55 | 1304.7 | 0.82 | 89.7 |
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