CONICET | Buscador de Institutos y Recursos Humanos

This work deals with the piston failures foundin diesel engines functioning in light trucks. The failurewas a hole inside the bowl located at the top of the piston,which is the combustion chamber of the engine. This holeprogressed and finds its way out between the second andthird rings. The operational characteristics of the enginewere analyzed in order to elucidate the probable actingfailure mechanisms. For the evaluation, obviously wereassessed the damaged pistons but also pistons of the sameengine without the mentioned failure and a new piston.Different studies and measurements were carried out suchas microstructural morphologies and transformations,hardness, fracture surface analysis and chemical composition.The piston design, the material used and theoperational conditions (thermal and mechanical) werestudied with the purpose of determining the failure origin.It was concluded that thermomechanical fatigue along withsome degree of degradation suffered by the material isresponsible of the reported failure.