The derailments accident of railroad suffer a large number of casualties, and it occurred sometimes all over the world even now. Many causes of the derailment accident are that the wheel runs on a rail by high friction coefficient contact between the wheel flange and the rail. So, normally the lubricating oil is used in order to prevent the high coefficient contact. However, it has many problems to use the oil, for example oil maintenance cost and care for environmental problems. In this study, in order to achieve the low friction coefficient without using the lubricating oil, the surface modification treatment which indicates excellent tribological properties was suggested, especially DLC (Diamond Like Carbon) coating. Model wheels coated surface modifications were prepared. The friction and abrasion tests assumed actual condition were carried out. It is clear that to coat DLC only has no effect, so it is important to combine two or more surface modifications. By combining the surface modifications, it can be achieved low friction coefficient contact between the wheel flange and the rail without using the lubricating oil enough to prevent the derailments. Further more, in order to achieve more safety wheel, hybrid-MoS2 coating was performed. This wheel indicated significantly low friction coefficient. It is possible to achieve security and safety wheel which can prevent the derailments by using hybrid-DLC and hybrid-MoS2 coating.
