Inhibition Behaviour of Some Isonicotinic Acid Hydrazides on the Corrosion of Mild Steel in Hydrochloric Acid Solution

Table 5

Impedance parameters for corrosion of MS in 0.5 M HCl in the absence and presence of different concentrations of INIMH and INPMH at 30°C.

Inhibitors	Concentration; (in ppm)	𝑅𝑝 (Ω cm^2)	𝐶𝑑𝑙 (μF Cm^−2)	IE (%)
Blank	0	177.5	149.60	—
INIMH	200	562.8	35.32	68.46
	300	759.3	27.97	76.62
	400	870.7	27.17	79.61
	500	1192.0	23.27	85.10
INPMH	200	537.5	39.51	66.97
	300	645.2	33.12	72.48
	400	817.2	29.62	78.27
	500	1081.0	27.69	83.58