Cavitation Resistance of a Cr-Mn Stainless Steel, A Mild Steel, and A High-Carbon Steel Based on Rust Protectivity and Corrosion Behavior

The cavitation erosion performance of a mild steel, a high-carbon steel, and a Cr-Mn stainless steel was studied in 3.5 wt.% NaCl solution using a probe-type ultra-sonicator device. The cavitation behavior of the steels was analyzed in terms of the mean depth of erosion (MDE) and the mean depth erosion rate (MDER). The dynamic polarization tests were performed in the same chloride solution. The micro-mechanism of the cavitation behavior of the steels was investigated with the help of scanning electron microscopy and Raman spectroscopic analysis. The cavitation resistance of the high-carbon and the stainless steels was found to be ~2.5 and ~50 times better than that of the mild steel. The corrosion resistance of the high-carbon and stainless steels was found to be ~2 and ~21 times higher than that of the mild steel, respectively. Afterward, a strong influence of the corrosion resistance of the steels on the cavitation performance was investigated on the basis of corroded surface morphology. In addition, a strong correlation between cavitation resistance and corrosion products formed during cavitation was established. Cavitation erosion resistance of the steels is precisely predicted by the protective ability index (PAI) without the need for any mechanical characterization.