Erosion-corrosion of X-52 steel pipe under turbulent swirling impinging jets

Erosion-corrosion tests were carried out at two regimes, non-swirling jets with swirl number (S=0), and weakly swirling jets up to reaching vortex breakdown (S=0.1, 0.2 and 0.3); the average flow velocity was adjusted at 3.2 ms−1, meanwhile the corrosive media consisted of 1 l of distilled water and 2 g/l NaCl purged with CO2 and abrasive particles of 20 μm of aluminium oxide (Al2O3) suspended into test solution with a content of 11 kg m−3. The impinging angle was 90 ° in the near-field. Electrochemical measurements were performed using the polarization resistance technique (Rp). Furthermore, to characterize the damaged surface, optical and scanning electron microscopy (SEM) images were taken, also the corrosion products were analyzed by means of X-ray diffraction (XRD) and EDS techniques to identify the material loss mechanism. The experimental results shows that the maximum corrosion rate was observed at high swirl numbers, moreover, this swirling regime is more severe than the non-swirling condition improving the pit formation.