ABSTRACT

The effect of nitrogen on the pitting process is investigated using the electrochemical noise (EN) approach in 0.01 M FeCl₃ for 24 h at a sampling frequency of 1 Hz. The EN signals were investigated using wavelet analysis on four alloys of 316L SS containing varying quantities of nitrogen (0.07, 0.12, 0.14 and 0.22 wt-% nitrogen). Using an energy distribution (ED) and standard deviation of partial signal (SDPS) plot, the primary corrosion process in various nitrogen-containing 316L SS was found. The ED plot showed that as the nitrogen percentage in the alloy increased, the energy of the low-frequency signal decreased, indicating that long-time transients were suppressed. The SDPS figure revealed a drop in pit density as nitrogen levels increased. For specimens containing 0.07, 0.11, 0.14 and 0.22 wt-% nitrogen, the pit density was determined to be 439 ± 8, 383 ± 6, 212 ± 6 and 108 ± 4 pits mm⁻², respectively.

摘要

_{使用电化学噪声 (EN) 方法在 0.01 M FeCl 3}中研究氮对点蚀过程的影响以 1 Hz 的采样频率持续 24 小时。使用小波分析对四种含有不同量氮（0.07、0.12、0.14 和 0.22 wt-% 氮）的 316L SS 合金进行 EN 信号分析。使用能量分布 (ED) 和部分信号的标准偏差 (SDPS) 图，发现了各种含氮 316L SS 中的主要腐蚀过程。ED图显示，随着合金中氮含量的增加，低频信号的能量降低，表明长时间瞬变被抑制。SDPS 数据显示，随着氮含量的增加，坑密度下降。对于含有 0.07、0.11、0.14 和 0.22 wt-% 氮的试样，凹坑密度分别确定为 439 ± 8、383 ± 6、212 ± 6 和 108 ± 4 个凹坑 mm ^-2。