Effect of ultrasonically induced cavitation on inhibition behavior of polyethylene glycol on carbon steel corrosion

In this investigation the influence of 24 kHz ultrasound wave upon the corrosion of carbon steel in 3 N sulphuric acid at 25 °C in the presence of inhibitors was studied. The inhibitors were polyethylene glycols (PEG) in different molecular weights (from 400 up to 10,000 g mol−1). The polarization and impedance spectroscopy results show the effectiveness of polyethylene glycols on the cavitation–corrosion inhibition of carbon steel in sulphuric acid. The inhibition efficiency is increased with increasing mean molecular weight of polymer and its concentration. The weight loss method has confirmed these results. The analysis of SEM images indicates that these inhibitors prevent propagation of pits on the eroded specimen. The inhibition effect of PEGs can be attributed to cushioning effect of adsorbed polymers on cavitation phenomenon produced by bubble collapse.