Inhibitory Mechanism of Carbon Steel Corrosion in Sea Water by an Aqueous Extract of Henna Leaves

Table 7

AFM data for carbon steel surface immersed in inhibited and uninhibited environment.

Samples	RMS (𝑅𝑞) roughness (nm)	Average (𝑅𝑎) roughness (nm)	Maximum peak-to-valley height (nm)
(1) Polished carbon steel (Control)	4.33	3.41	35.28
(2) Carbon steel immersed in sea water (blank)	17.10	13.58	92.28
(3) Carbon steel immersed in sea water + HE (8 mL); + Zn^2+ 25 (ppm)	11.8	7.65	27.47