Comparison Between the Magnetic Properties of Ball Milled Nanocrystalline Perlitic Steel and the Running Surface of Rails in High Speed Railway Tracks

摘要

It is well known that the magnetic Barkhausen noise (MBN) depends amongrnothers on the grain size. This dependence was investigated in detail in manyrnearlier works, but only on microcrystalline materials. However, it is notrnknown whether these relationships are also valid or not in nanocrystallinernstate (when the grain size is less then 100 nm). This can be very importantrnin the understanding of the formation of surface corrugation, caused by thernsurface loading and can be related to the formation of a nanocrystallinernlayer. In our measurements ball milling of rails was carried out in order tornmodel the formation of the nanocrystalline layer and to enable therninvestigation of the relationship between the grain size and the magneticrnproperties. On-site measurements on railway tracks were also carried out andrnwill be discussed.