Susceptibility of materials to cavitation erosion in Hong Kong

The authors studied the cavitation erosion and corrosion behaviors of materials - copper, brass, bronze, cast iron, and stainless steel - commonly used in water supply systems in Hong Kong. An ultrasonic vibration system was used to estimate the cavitation erosion for both local tap water and deionized water. Polarization technique was used to study the corrosion behavior of materials in tap water; the contributions of mechanical erosion, corrosion, and erosion-corrosion were also investigated. The resistance of these materials to cavitation erosion for local tap water was ranked (in decreasing order of resistance) as follows: stainless steel, brass, bronze, cast iron, and copper. The authors propose, based on their findings, a simple formula for estimating the fractional increase in metal release attributable to cavitation erosion.