Pitting corrosion inhibition of some copper alloys in NaCl solutions by straight chain carboxylates

ABSTRACT

Electrochemical methods were used to investigate the abilities of the homologous straight chain monocarboxylates [C[n]H[2n+1]COO, n=1-13] to inhibit the pitting corrosion of two types of copper alloys in NaCl solutions. The copper alloys were alloy [I] [Cu + 4.47% Fe] and alloy [II] [Cu + 10.67% Al + 5.02% Fe]. It was found that these were susceptible to pitting corrosion in NaCl solutions, with increase of Cl[-] ions concentration. Alloy [II] was more susceptible to pitting corrosion than alloy [I]. The inhibition performance of the monocarboxylates was critically dependent upon their chain length. The range of chain lengths producing optimal inhibition efficiency was [6 ability outside the optimal range. The dramatic variations in inhibition efficiencies probably resulted from competing reactions such as adsorption, solubility and micelle formation