Failure Analysis on Crankshaft Thrust Plate of Large Ship

A number of radial cracks were found in a crankshaft thrust plate of marine diesel engine during working. Then, the thrust plate fractured in the subsequent process of repair. Macro examination, chemical composition analysis, mechanical property test, metallurgical structure examination, TEM analysis, and SEM observation were used to study the fracture reason of the thrust plate. The results indicate that the original cracks formed during working were not removed in the repair process, leading to the subsequent propagation of cracks; In addition, the higher brittleness of the material and the thermal stress caused by improper induction heating in the repair process promoted the cracking failure of the thrust plate.