Failure Analysis on Cracking of Engine High Pressure Fuel Pump Barrels

A certain engine high pressure fuel pump barrels cracking accident happened in a period of time and it was analyzed by means of SEM, EDS, hardness tester and optical microscope. The results indicate that the main cause for the cracking was the poor inner quality of the barrel material. There was serious banded carbide which caused intergranular banding fracture at the fatigue cracking source area. Moreover, high pressure fuel pump barrels disassembled from the engine in use were tested to estimate the failure accident probability. The analysis results provided a reliable technical evidence to treat this quality accident.