Failure mechanism in the pearlite structure with lamellar graphite due to temperature

Critical operating temperature can be determined for the machine components that form key functional part of device. This article describes a change failure mechanism in material an engine, where structure consists fine pearlite layers with lamellar graphite equivalent to grey cast iron. The mechanical properties this influence not only formed by perlite, but also acting as stress concentrator. To assess material, fractographic analysis fracture areas was performed after impact test. range test temperatures at which on specimens notch ranged from -80°C +180°C. occurrence brittle detected low cleavage along and over planar graphite. initiation higher observed basic layer perlite. Depending area, critical were determined, measured value toughness decreased. Regression dependence allows very precise quantification decrease.