Table 5.
Corrosion rate and inhibitory efficacy of NSQN & CSQN at a concentration of 1×10 −3 M as a function of temperature for M-steel in 1.0 M HCl.
| Medium | T (K) | -Ecorr (mV/SCE) | icorr (μA cm−2) | Tafel slopes (mV dec−1) |
EPP(%) | |
|---|---|---|---|---|---|---|
| βc | βa | |||||
| Blank | 303 | -496.0 | 556 | -105.0 | 55.4 | — |
| 313 | -454.0 | 860 | -80.0 | 69.0 | — | |
| 323 | -443.0 | 1840 | -87.0 | 96.0 | — | |
| 333 | -450.0 | 2600 | -86.7 | 106.9 | — | |
| NSQN | 303 | -410.5 | 30 | -128.5 | 76.5 | 94.0 |
| 313 | -383.4 | 198 | -188.4 | 57.0 | 76.9 | |
| 323 | -460.0 | 677 | -233.1 | 155.0 | 62.5 | |
| 333 | -417.0 | 1159 | -179.1 | 89.3 | 55.4 | |
| CSQN | 303 | -424.8 | 50 | -99.2 | 67.3 | 91.0 |
| 313 | -442.2 | 239 | -170.8 | 112.7 | 72.2 | |
| 323 | -435.0 | 811 | -186.0 | 111.3 | 55.9 | |
| 333 | -457.6 | 1376 | -232.2 | 114.5 | 47.0 | |