Table 3.

Potentiodynamic polarization parameters such as corrosion potential (E_corr), corrosion current density (i_corr) and anodic and cathodic Tafel slopes (b_a and b_c) using different inhibitors.

Without KI							With KI
Inhibitor	Conc. (ppm)	−Ecorr (mV)	icorr (× 10−3) (µA)	bc (mV/dec)	ba (mV/dec)	% IEP	−Ecorr (mV)	icorr (× 10−3) (µA)	bc (mV/dec)	ba (mV/dec)	% IEP
Blank	-	742	1792	29	165	-	742	1792	29	165	-
Pc1	25	706	420	23	121	76.5	698	273	13	111	84.5
	50	707	334	20	167	81.4	695	393	14	128	84.8
	100	705	289	15	137	83.9	680	173	14	71	90.3
Pc2	25	707	532	34	154	70.3	705	409	11	110	77.2
	50	706	398	14	91	77.8	709	226	9	63	87.4
	100	695	269	18	100	85.0	708	405	17	124	77.4
Pc3	25	704	290	13	160	83.8	698	301	13	120	83.2
	50	710	332	12	139	81.5	700	421	2	137	76.5
	100	711	451	20	136	74.8	695	235	10	128	86.9
Pc4	25	437	832	78	79	83.0	704	398	17	115	77.8
	50	735	1209	24	146	76.9	705	373	13	131	79.2
	100	731	1031	21	147	74.2	684	152	24	117	91.5
nPc1	25	709	101	51	200	70.0	700	221	17	119	87.7
	50	705	294	11	138	86.1	699	324	33	142	81.9
	100	704	368	18	136	71.2	698	253	17	120	85.9
nPc2	25	704	280	10	104	84.3	671	17	11	46	99.1
	50	709	266	12	58	85.1	705	305	12	85	82.1
	100	707	158	29	147	91.2	707	506	13	125	71.0
nPc3	25	704	496	15	165	72.1	456	780	38	85	56.5
	50	701	613	29	105	65.3	685	116	19	124	93.5
	100	708	681	13	105	96.2	676	8	16	42	99.6