Effect of Nd³⁺ Ion Concentration on the Corrosion Resistance of API X70 Steel in Chloride-Rich Environments

Table 2

Evolution of electrochemical parameters of the EIS spectra after 100 hours of immersion in 3.5% NaCl solution.

Nd^3+ ion concentration	R1 (Ω-cm^2)	(μF·cm^−2)		R2 (Ω-cm^2)	(μF·cm^−2)		Rct (Ω-cm^2)	(μF·cm^−2)
0.0 M	—	—	—	—	—	—	848	1.63E − 3	0.65
0.0001 M	15.92	1.09E − 3	0.30	100.8	1.31E − 4	0.87	4677	1.06E − 3	0.63
0.0005 M	16.66	1.49E − 3	0.59	141.0	1.81E − 4	0.78	4971	4.14E − 4	0.69
0.001 M	22.85	3.98E − 5	0.69	161.4	1.82E − 4	0.74	5950	2.02E − 4	0.76
0.005 M	19.87	4.80E − 5	0.69	41.0	5.03E − 5	0.90	5886	2.94E − 4	0.66
0.01 M	22.24	2.03E − 3	0.60	7.9	1.59E − 4	0.81	5770	1.71E − 4	0.42