Low cycle fatigue of nodular cast iron used for railway brake discs

The objective of the present paper is to evaluate the fatigue life of nodular cast iron EN-GJS-500-7, used for railway brake discs. Tension and low-cycle fatigue properties were examined at room temperature (RT), 300 °C and 400 °C. Microstructure of the material was documented at RT and 400 °C. Tensile stress–strain curves, cyclic hardening/softening curves, cyclic stress–strain curves, stress–strain hysteresis loops and fatigue life curves were obtained for all temperatures. Young’s modulus remained quite temperature stable, while proof stress and ultimate tensile strength decreased with increasing temperature. Fatigue life decreased for around 50% at 300 °C, while at 400 °C samples endured to only 10% of strain reversals of those at RT.