Reasons for cracking of starch centrifuge drum

Cracks were found on the bottom surface of a starch centrifuge drum. The reasons for the cracking of the centrifuge drum were analyzed using macroscopic observation, chemical composition analysis, scanning electron microscopy and energy spectrum analysis, metallographic examination. The results show that the inner surface of the drum did not smoothly transition during the processing, causing stress concentration in the groove area. Under the action of corrosive chloride ions, the drum underwent stress corrosion cracking. The hard and brittle σ phase precipitated in the material structure of the rotary drum, and there were localized chromium poor areas around the precipitated phase, further promoted the propagation of cracks.