Una famiglia di acciai innovativi per ruote monoblocco forgiate-laminate progettati per ambienti sabbiosi

The report describes the properties of a new steel grade family for forged-rolled solid wheels alternative to AAR Class B/C/D steel grades, designed to increase the resistance to wear and rolling contact fatigue (RCF) also in presence of sand and other solid contaminants. The study of the effects of the solid contaminants at the wheel-rail interface has been carried out by means of metallurgical investigations on full scale wheels tested in deserts, small-scale laboratory experiments by a bi-disc rig and Finite Element analysies (FEM). As a result, a micro-alloyed steel
grade family named SANDLOS®, suited for forged and rolled wheels, has been designed and developed, characterized by higher values of Cyclic Yield Strength with respect to the average values of the corresponding AAR standards, even in the respect of the same standard. The special characterization of the new steel grade family is performed according to common criteria designed by Lucchini RS; performances improvement is obtained through various indices/maps allowing the comparison with traditional grade steels.