THIOUREA FORMALDEHYDE AS AN EFFECTIVE CORROSION INHIBITOR FOR N80 STEEL IN 3.5 NACL SOLUTION SATURATED WITH CO2

摘要

Thiourea formaldehyde (TF) was used to investigate the inhibition efficiency on corrosion of N80 steel in CO2 saturated 3.5% NaCl through AC impedance, polarization curves, scanning electrochemical microscopy (SECM), SEM, FTIR, techniques. The Nyquist diagrams showed increase in R_(ct) values in the presence of TF, thus increasing inhibition efficiency. Potentiodynamic curves suggested that the inhibitor is mixed type in nature. Scanning electrochemical microscopy (SECM) revealed the action of protection by inhibitor acting as an insulator. The surface analysis through SEM for N80 specimens also proved the results obtained by the electrochemical experiments.