Quantification of Metal Loss Due to Silt Erosion under Laboratory Conditions

Mild steel test specimen set at angles of 50, 450 and 900 in the slurry flow direction were exposed to silt attack in a pot test rig in the laboratory. The total period of exposure of the specimen to the silt attack was maintained for four hours, at steps of one hour interval each. Sio2 particles in the size range of 90-250μm were embedded in tap water to constitute the slurry. The slurry concentration was maintained at 7500 ppm. The shaft carrying the test specimen was rotated at 4032rpm in the slurry to maintain an equivalent water head of 89.85metres. The surface hardness of the specimen increased progressively with the increase in the time of exposure. Maximum Average metal loss was recorded for the sample inclined at 450 in the direction of silt flow while it was minimum for the 900 samples. The experimental results were in good agreement with the theoretical calculated value for metal loss obtained using finnie's model.