Abstract: The centrifuge drum of a company fractured after only one year of service. The fracture causes of drum were analyzed by means of macroscopic analysis, chemical composition analysis, hardness test, mechanical property test, metallographic examination, scanning electron microscope analysis and energy spectrum analysis. The results show that there were a lot of hard and brittle σ phase in the microstructure of the drum made of duplex stainless steel due to improper operation during solution treatment. When the drum was running at high speed, a large centrifugal force will be generated. Under the action of centrifugal force, cracks will be initiated and propagated in the dense part of σ phase, which eventually led to the fracture of the drum.