Vliv modifikací tepelného zpracování na tvrdosti věnců železničních kol

Abstract

Dissertation named „Influence of Heat Treatment Modifications on to Railway Wheel Rim Hardness“ describes how mechanical characteristics depend on microstructure by using comparison of vaules of individual tests as hardness test, thougness test, grain size test and material homogenity. Each testing is focused on to the wheel rim part. There is specified material R7 which is mainly used for freight transport, heat tratment, testing of mechanical characteristics and microstructure testing as well. All particular processes are described generally first and then follow descriptions of process´realisation in Bonatrans Group a.s. Conclusion part covers comparison of microstructures by different values of mechanical characteristics of wheel rim and validity of Hall-Petch relation