Wear and friction behavior of austempered ductile iron as railway wheel material

Austempered ductile irons (ADIs) with three strength grades and one kind of wheel steel were matched with conventional rail steel and rolling-sliding wear tests were conducted. The results show that the wear rate decreases while the friction coefficient increases with the increase of matrix hardness. The increase of subsurface hardness is due to work-hardening and stain-induced transformation of retained austenite to martensite. The main wear mechanism is delamination and becomes mild with the increase of matrix hardness. ADI austempered at 340 degrees C shows the reasonable friction and wear behavior as well as relatively superior mechanical properties. (C) 2015 Elsevier Ltd. All rights reserved.