Influence of iron microstructure on the performance of polyacrylic acid as corrosion inhibitor in sulfuric acid solution

The corrosion inhibition behavior of bulk nanocrystalline ingot iron (BNII) fabricated from coarse polycrystalline ingot iron (CPII) by severe rolling technique by polyacrylic acid (PAA) was studied in 0.1 M H2SO4 using electrochemical impedance spectroscopy and potentiodynamic polarization techniques. The results indicated that PAA inhibited the acid induced corrosion of both iron specimens, with greater effect noted for BNII. The corrosion inhibiting effect was influenced by the microstructure of the iron samples. Synergistic inhibition effect was observed on addition of iodide ions to PAA in case of CPII while for BNII inhibition efficiency marginally increased.

Research highlights
► BNII is fabricated from CPII by severe rolling technique.
► BNII was more susceptible to corrosion in the uninhibited acid.
► The corrosion and corrosion inhibiting effect was influenced by the microstructure of the Fe samples.
► Inhibition efficiency was greatly enhanced on addition of iodide ions to PAA for CPII compared to BNII.