Expired concor drug as potential nontoxic corrosion inhibitor for 304 stainless steel in hydrochloric acid solution

Abstract

The effect of the expired concor drug as the corrosion inhibitor for stainless steel type 304 (304SS) in 2M HCl solution has been investigated using electrochemical and non-electrochemical techniques. Some kinetic corrosion parameters were calculated. The inhibition efficiency (% I) increases with rising concentration of the drug and maximum efficiency (85.8 %) reached 300 ppm. The polarization measurements indicated that the expired concor drug was of the mixed type and inhibits corrosion by adsorption on the surface of 304SS due to the presence of more than one active center in its molecule. The adsorption was obeyed Langmuir adsorption isotherm. The activation energy and thermodynamic parameters were also calculated and discussed.Efekat vremenski isteklog leka kao inhibitora korozije za nerđajući čelik tipa 304 (304SS) u 2M HCl rastvoru je ispitan korišćenjem elektrohemijskih i ne-elektrohemijskih tehnika. Izračunati su neki parametri kinetičke korozije. Efikasnost inhibicije (% I) povećava se sa rastućom koncentracijom leka i maksimalna efikasnost (85,8%) je dostigla 300 ppm. Polarizacijska merenja pokazala su da je vremenski istekli lek bio inhibitor mešovitog tipa i inhibirao je koroziju adsorpcijom na površini 304SS zbog prisustva više od jednog aktivnog centra u njegovom molekulu. Adsorpcija se ponašala po izotermi adsorpcije Langmira. Takođe, proračunati su i razmatrani energija aktivacije i termodinamički parametri.