Inhibitory Action of Artemisia annua Extracts and Artemisinin on the Corrosion of Mild Steel in H₂SO₄ Solution

Table 2

Calculated values of the corrosion rate and inhibition efficiency for mild steel coupons in 1.0 M H₂SO₄ solutions in the absence and presence of inhibitors (using the weight loss technique).

Inhibitor	System	Corrosion rates (mg cm^−2 hr^−1)	Inhibition efficiency (%)
	Blank	1.406	—
EEAA	0.1 gL^−1 EEAA + 5 M H2SO4	1.040	26.00
	0.5 gL^−1 EEAA + 5 M H2SO4	0.886	37.02
	1.0 gL^−1 EEAA + 5 M H2SO4	0.703	50.01
	2.0 gL^−1 EEAA + 5 M H2SO4	0.366	74.00
	4.0 gL^−1 EEAA + 5 M H2SO4	0.064	95.48
AEAA	0.1 gL^−1 AEAA + 5 M H2SO4	0.886	37.02
	0.5 gL^−1 AEAA + 5 M H2SO4	0.515	63.35
	1.0 gL^−1 AEAA + 5 M H2SO4	0.414	70.55
	2.0 gL^−1 AEAA + 5 M H2SO4	0.206	85.36
	4.0 gL^−1 AEAA + 5 M H2SO4	0.105	92.54
ATS	20 mgL^−1 ATS + 5 M H2SO4	1.266	9.97
	50 mgL^−1 ATS + 5 M H2SO4	1.172	16.61
	100 mgL^−1 ATS + 5 M H2SO4	1.159	17.55
	200 mgL^−1 ATS + 5 M H2SO4	1.153	17.98
	400 mgL^−1 ATS + 5 M H2SO4	1.071	23.81