Determination of Fracture Toughness of Rail UIC60 Steel using Charpy Impact Test in Different Temperatures

Nowadays, railway has been identified as the safest and most proper transportation system. Failure of rails, as one of the most importance elements of railway systems, can cause accidents and affect its safety. In this study, 55 steel samples extracted from UIC60 rail have been tested by Charpy impact test equipment in different temperatures ranged between -40 and 60 C. Then, fracture toughness of rail in different temperatures has been calculated by using known experimental relation between fracture toughness and measured fracture energy. Finally, the rail critical crack length has been determined by replacing calculated fracture toughness in formula of stress intensity factor. In order to restrict rail fracture and increase service life of the rail, critical crack length, in addition to none destructive tests for maintenance process of rails