Figure 1.
The potentiodynamic curves of 4130 Cr-Mo alloy steel in thioacetamide solution at different immersion times: 10, 20 and 30 h at 80 °C, pH 2.
Figure 1.
The potentiodynamic curves of 4130 Cr-Mo alloy steel in thioacetamide solution at different immersion times: 10, 20 and 30 h at 80 °C, pH 2.
Figure 2.
The potentiodynamic curves of 4130 Cr-Mo alloy steel in thioacetamide solution at different immersion times: 10, 20 and 30 h at 80 °C, pH 5.
Figure 2.
The potentiodynamic curves of 4130 Cr-Mo alloy steel in thioacetamide solution at different immersion times: 10, 20 and 30 h at 80 °C, pH 5.
Figure 3.
The potentiodynamic curves of 4130 Cr-Mo alloy steel covered with elemental sulfur in 3.5% sodium chloride solution at different immersion times: 10, 20 and 30 h at 80 °C, pH 2.
Figure 3.
The potentiodynamic curves of 4130 Cr-Mo alloy steel covered with elemental sulfur in 3.5% sodium chloride solution at different immersion times: 10, 20 and 30 h at 80 °C, pH 2.
Figure 4.
The potentiodynamic curves of 4130 Cr-Mo alloy steel covered with elemental sulfur in 3.5% sodium chloride solution at different immersion times: 10, 20 and 30 hat pH 5.
Figure 4.
The potentiodynamic curves of 4130 Cr-Mo alloy steel covered with elemental sulfur in 3.5% sodium chloride solution at different immersion times: 10, 20 and 30 hat pH 5.
Figure 5.
SEM micrograph and EDS of the corrosion product layers that form on the surface of each sample at pH 2 under (a) 10, (b) 20 and (c) 30 h immersion time in thioacetamide solution.
Figure 5.
SEM micrograph and EDS of the corrosion product layers that form on the surface of each sample at pH 2 under (a) 10, (b) 20 and (c) 30 h immersion time in thioacetamide solution.
Figure 6.
SEM micrograph and EDS of the corrosion product layers that form on the surface of each sample at pH 5 under (a) 10, (b) 20 and (c) 30 h immersion time in thioacetamide solution.
Figure 6.
SEM micrograph and EDS of the corrosion product layers that form on the surface of each sample at pH 5 under (a) 10, (b) 20 and (c) 30 h immersion time in thioacetamide solution.
Figure 7.
SEM micrograph and EDS of the corrosion product layers that form on the surface of each sample covered with elemental sulfur at pH 2 under (a) 10, (b) 20 and (c) 30 h immersion time.
Figure 7.
SEM micrograph and EDS of the corrosion product layers that form on the surface of each sample covered with elemental sulfur at pH 2 under (a) 10, (b) 20 and (c) 30 h immersion time.
Figure 8.
SEM micrograph of the corrosion product layers that form on the surface of each sample covered with elemental sulfur at pH 5 under (a) 10, (b) 20 and (c) 30 h immersion time.
Figure 8.
SEM micrograph of the corrosion product layers that form on the surface of each sample covered with elemental sulfur at pH 5 under (a) 10, (b) 20 and (c) 30 h immersion time.
Figure 9.
Cross-section of corrosion product layer of the (a) first and (b) second series of experiments at pH 5 after 10 h immersion time.
Figure 9.
Cross-section of corrosion product layer of the (a) first and (b) second series of experiments at pH 5 after 10 h immersion time.
Figure 10.
XRD pattern for the samples in (a) the second series of experiment at pH 5 after 30 h immersion, (b) the first series of experiments at pH 5 after 10 h immersion and (c) the second series of experiment at pH 5 after 10 h immersion.
Figure 10.
XRD pattern for the samples in (a) the second series of experiment at pH 5 after 30 h immersion, (b) the first series of experiments at pH 5 after 10 h immersion and (c) the second series of experiment at pH 5 after 10 h immersion.
Table 1.
Experimental condition of the first series.
Table 1.
Experimental condition of the first series.
Condition No. | T (°C) | pH | Immersion Time (h) |
---|
1 | 80 | 2 | 10 |
2 | 80 | 2 | 20 |
3 | 80 | 2 | 30 |
4 | 80 | 5 | 10 |
5 | 80 | 5 | 20 |
6 | 80 | 5 | 30 |
Table 2.
Experimental condition of the second series.
Table 2.
Experimental condition of the second series.
Condition No. | T (°C) | PH | Immersion Time (h) |
---|
7 | 80 | 2 | 10 |
8 | 80 | 2 | 20 |
9 | 80 | 2 | 30 |
10 | 80 | 5 | 10 |
11 | 80 | 5 | 20 |
12 | 80 | 5 | 30 |
Table 3.
The values of anodic () and cathodic () Tafel slopes of first series.
Table 3.
The values of anodic () and cathodic () Tafel slopes of first series.
Experiment | (mV·Decade−1) | (mV·Decade−1) |
---|
1 | 0.022 | 0.019 |
2 | 0.029 | 0.020 |
3 | 0.020 | 0.019 |
4 | 0.034 | 0.023 |
5 | 0.021 | 0.018 |
6 | 0.028 | 0.020 |
Table 4.
The corrosion rate of the first series.
Table 4.
The corrosion rate of the first series.
Experiment | 1 | 2 | 6 | 4 | 5 | 6 |
---|
pH | 2 | 2 | 2 | 5 | 5 | 5 |
Corrosion Rate (CR) (mm/year) | 0.368 | 0.325 | 0.318 | 0.066 | 0.044 | 0.224 |
Table 5.
The values of anodic () and cathodic () Tafel slopes of second series.
Table 5.
The values of anodic () and cathodic () Tafel slopes of second series.
Experiment | (mV·Decade−1) | (mV·Decade−1) |
---|
7 | 0.032 | 0.015 |
8 | 0.030 | 0.013 |
9 | 0.023 | 0.020 |
10 | 0.022 | 0.021 |
11 | 0.022 | 0.019 |
12 | 0.020 | 0.019 |
Table 6.
The corrosion rates of second series.
Table 6.
The corrosion rates of second series.
Experiment | 7 | 8 | 9 | 10 | 11 | 12 |
---|
pH | 2 | 2 | 2 | 5 | 5 | 5 |
Corrosion Rate (CR) (mm/year) | 0.615 | 0.605 | 0.595 | 0.381 | 0.367 | 0.318 |