Publications

The corrosion of mild steel (MS) and AISI type 321 stainless steel (AISI 321) in 1 M HCl solution and the inhibitive mechanism of N,N,N′,N′-Tetramethyl-p-phenylenediamine (TMPPD) were investigated using open circuit potential measurements (OCP), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Potential-time measurements showed that the addition of TMPPD to HCl solutions shifts the potential of MS and AISI 321 to more positive values. Polarization curves measurements indicated that TMPPD act as a mixed type inhibitor for the corrosion of MS and AISI 321 in HCl solutions. EIS measurements showed that the dissolution process occurs under activation control. The applied techniques explained that TMPPD is more efficient as a corrosion inhibitor for mild steel than stainless steel in acidic solutions. Theoretical fitting of different isotherms, Langmuir, Kinetic-thermodynamic, Flory–Huggins, and Temkin isotherms were tested to explain the nature of TMPPD adsorption. The associated activation parameters were also calculated and discussed.