Cavitation Erosion-A case of conjoint action

Cavitation erosion has been attributed to a conjointed action of chemical and mechanical factors giving rise to a very serious type of erosion. A case of serious failure of cast iron pump impeller by cavitation erosion investigated at the National Metallurgical Laboratory, showed that the hammering effect of collapsing cavities and corrosion by chlorides and chlorine were the root cause of attack. Preventive measures suggested in this connection include control of water pressure head at the pump inlet, choice of metal, perfection in design etc. (Mr. A.K. Lahiri, Junior Scientific Officer and Dr. T. Banerjee, Deputy Director, National Metallurgical Laboratory, Jamshedpur)