Failure Analysis of Water Pump Shaft

A number of shaft failures were encountered in water recirculation pumps of an industrial setup. The shafts were made of martensitic stainless steel. A detailed study was carried out to determine the cause of the pump shaft failures. In this connection, the analyses performed include chemical analysis, microstructural characterization, fractography, tensile, shear, and hardness measurement. The chemical composition of the shafts was as per standard, however, hardness was very low. It was concluded that the material was used without heat treatment, causing inferior properties (hardness, tensile, and shear). Experimental heat treatments were done to improve the properties of the shaft material.