Wear Behaviour of Austempered Ductile Iron

Castings are very widely used for critical friction and wear applications. As operating conditions are becoming more arduous, greater demands will be placed upon the casting industry to meet the requirements of the designer. This study was undertaken to evaluate the wear resistance of 2.5% Ni, 0.4% Mo austempered ductile iron, having a hardness of HB 270 and a high amount of retained austenite, in the particular context of a railway braking application. Pin-wear test data is presented, comparing wear behaviour of this ADI grade with that of a pearlitic grey cast iron which is currently employed as a brake block material in Iranian passenger trains, and with a 3% P cast iron which was developed in the UK.1