Abstract
Pipe wall thinning caused by liquid impingement erosion is one of the serious problems occurred in piping systems of electric power plants. Liquid impingement erosion is thought to have the threshold velocity that erosion does not occur or erosion rate is vanishingly small. It was reported that a threshold velocity is 100m/s for a pure iron and 110m/s for a carbon steel by Shimogaya, and 70m/s for stainless steel by Mittsubishi Heavy Industries, Ltd. In general, it is highly unlikely that, however, a stainless steel with high work-hardening is eroded faster than a carbon steel. Therefore, liquid impingement erosion tests were carried out for a S15C carbon steel and a SUS304 stainless steel to clarify the flow velocity dependence and the threshold velocity of liquid impingement erosion. It was found that threshold velocity is 80m/s for a S15C and 120m/s for a SUS304. Also, we clarified the erosion mechanism due to liquid impingement by scanning electron microscopy.
