Mechanical and wear behaviour of alloyed hypereutectic grey cast iron

Abstract

Alloyed grey cast iron is an important automotive material used in clutch and brake applications. In order to understand the influence of microalloying additives on the graphitic morphology, mechanical and wear behaviour, a series of microalloyed cast iron melts were taken. The laboratory scale ingots made were characterised for microstructure, mechanical properties and wear behaviour. All the cast irons made were hypereutectic with a microstructure consisting of class A type graphite in a pearlitic matrix with eutectic grain boundary carbides. The microalloyed cast irons showed two- to threefold improved wear resistance over a base unalloyed material at comparable mechanical strengths. The wear loss was found to be linear with increasing sliding distance, and the wear resistance is attributed to the combined influence of dense pearlitic matrix with carbides and good distribution of graphite flakes. Cast iron microalloyed with Ni (0·62%) with Ce inoculation showed best overall properties compared to other alloys.