Slurry erosion studies of hydroturbine steels under hydroaccelerated conditions

Abstract

Degradation of the hydroturbine components due to slurry erosion is a serious issue, especially for the hydropower plants situated on the rivers originating from Himalayas in India. In the current investigation, slurry erosion performance of two stainless steels (CA6NM and CF8M), which are commonly used in hydroturbine power plants, has been studied. A high-speed erosion test apparatus was used for the studies. Slurry collected from an actual hydropower plant was used as the abrasive media in the test apparatus. The effect of slurry concentration (ppm), average particle size of slurry particles and rotational speed on the slurry erosion behaviour was investigated under different experimental conditions. The analysis of eroded samples was done using scanning electron microscopy (SEM) and stylus profilometry. SEM images showed signatures of formation of lips, ploughing, crater and microcutting on eroded surface of steels.