A certain number of railway brake discs made of gray cast iron, showed the presence of small cracks only after a few thousand kilometers. To investigate main causes of a brake disc failure, numerical analysis was done by using ABAQUS software. Numerical analysis resulted from a physical model of heat flux in dependence of braking time. Physical model was applied considering all demands and presumptions given by industry representatives. © 2011 Shanghai Jiaotong University and Springer-Verlag Berlin Heidelberg.