engleski

Failure analysis of high-pressure fuel injection lines

This paper presents the results of the failure analysis of high-pressure fuel injection lines of a diesel engine that caused fire on the public transportation bus. Fuel injection lines had been in operation for 18 months, and two of them were cracked at the point where they were connected to the engine injector. These damages caused fuel leaks and finally fire on the bus which spread into the passenger cabin and caused significant damage. The failure mechanism was analysed by both visual and SEM inspection of the fracture surface, identifying fatigue as the major cause of the final failure. Microstructure analyses, microhardness measurements together with chemical analysis were performed in order to check any possible deviation in the material structure and/or composition. The results showed that fatigue failure occurred due to the decarburization of the outer surface of the high- pressure lines.

High-pressure fuel injection lines ; Failure analysis ; Decarburization ; Fatigue failure

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