Rolling/sliding wear resistance of steels with different microstructures

The present investigation has been focused on the wear resistance of carbide–free bainitic steels and other microstructures of steels like conventional bainite, pearlite and quench & tempered (Q&T) martensite. The material which is used to create a carbide-free bainitic microstructure has 0.6 %C and 1.73 %Si. The rolling–sliding wear tests are performed in tribology lab on a Twin disc machine. The results are analyzed by using optical microscope, SEM, Optical surface profiler, XRD and Vickers hardness test. The results showed that ausferritic steel has excellent wear resistance in comparison to steels with other microstructures. The wear rate difference between ausferritic and other steels is almost twice that of the difference between AF 250 and AF 300. This proves that the austempered ausferritic steel has a very good wear resistance. The other samples with pearlitic, quenched and tempered martensitic and bainitic microstructures showed higher wear rate. The deformed layer thickness is found to be deeper for steels with ausferritic microstructures and the hardness increased more than 300HV over the initial bulk hardness for these steels. This increase might be due to plastic deformation and to the strain induced martensitic transformation of the retained austenite. Steels with other microstructures as bainite, pearlite and quenched and tempered martensite showed an increase in hardness along with an increase in deformation layer thickness which was lower than for steels with ausferritic microstructures.Validerat; 20101217 (root