INFLUENCE OF NONMETALLIC INCLUSIONS ON CONTACT FATIGUE DEFECTS IN ZIRCONIUM CONTAINING RAILS

Investigations were carried out on trial batches of zirconium containing rails to establish the influence of non-metallic inclusions formed in rail steel deoxidised with complex alloys on contact fatigue damage to rails. The morphology, nature, and distribution of inclusions were studied on microsections taken from rails before and after tests. Metallographic, electron probe, and chemical methods were used, and petrographic data were referred to. The mechanical properties of rails were determined in static tensile tests and in impact bending tests. No correlation was found between mechanical properties and contact fatigue defects in rails of the trial batches.