A failure analysis study of wet liner in locomotive diesel engine

In this research, the effective factors on the liner failure of the turbocharged engine (16rk215T) of the locomotive have been investigated. By preparing three liner samples from different manufacturers and sending them to the laboratory, the mechanical properties, including hardness and tensile strength, as well as the percentage of constituent elements and the difference in their values in different samples, were studied. Next, the effect of the weight percentage of different elements on the mechanical properties of gray cast iron was investigated. By preparing microscopic images at 100x magnification, the background structure was seen. Also, the shape and arrangement of lamellar-graphite in different samples were compared with each other and it effect on the fracture and crack growth in the liner was investigated. Three samples of liner, grade and material have been determined. With the appearance of eutectic phosphide in the structures of two samples A (broken liner) and B (liner with crack), as well as the high percentage of phosphorus, structural defects and the presence of dislocations in the grain cause the failure of these samples. Also, non-uniform production of lamellar-graphite in these two samples, its short length and thickness increases strength, reduces absorption and reduces energy.