Abstrakt

Inhibitory Effect of SPT and Phosphonic acids controlling the Corrosion of Carbon Steel in Neutral Environment

B.Balanaga karthik , C.Thangavelu

The corrosion characteristics of carbon steel were investigated in the 60 ppm Cl- for a period of 3 days immersion in presence and absence of Zinc ions. This work comprises of laboratory studies. The experimental method included determination of corrosion rate by weight-loss method, EIS and Polarization studies. A large increase in charge transfer resistance and also decrease in double layer capacitance indicates that the formation of protective film on the surface. The ternary inhibitor system functions as an anodic inhibitor which is confirmed by Polarization study. The 25 ppm of SPT, 50 ppm DTPMP and 10 ppm Zn2+ gives maximum Inhibition Efficiency (IE) of 93%. The surface morphology of carbon steel was confirmed by SEM and AFM analysis.