The analysis of macro- and microstructure of the railway wheels made by different manufacturing methods

Purpose. The comparative studies of macro- and microstructure of the cast and all-rolled wheels. Methodology. The analysis of the macro- and microstructure of class C railway wheels, made according to the standard M-107 / M-208 manufacture by GriffinWheel, and all-rolled wheels of steel grade 2, made in accordance with ГОСТ 10791 - 2011 manufacture of PJSC ?Interpipe NTRP?. Findings. The macro- and microstructure studies of cast and all-rolled railway wheels have been carried out. Due to the features manufacture of the cast wheels (at first a rim crystallizes that is filled with liquid metal through a disk, then the disk and hud crystallize) all defects of cast structure (directional dendritic structure, shrinkage cavities, segregation of alloying and impurity elements) are observed in each elements of the cast railway wheels. It has been shown that contamination by non-metallic inclusions of cast wheels is more than 3 points, there are pores, expressed segregation and microstructure is heterogeneous. The microstructure of all elements of the cast wheel consists of pearlite. It has heterogeneous structure - strongly and weakly etched streaks (areas) due to the presence of dendritic segregation. The solid wheels' contamination by non-metallic inclusions did not exceed 2 points, pores are not observed. Their microstructure is homogeneous. Originality. It has been shown that contamination by non-metallic inclusions of the cast wheels is more than 3 points, there are pores, expressed segregation, and microstructure is heterogeneous. The contamination by non-metallic inclusions of the all-rolled wheels does not exceed 2 point, pores are not observed, and their microstructure is homogeneous. Practical value. The all-rolled railway wheels have greater operational reliability, so long as their quality is significantly higher by parameters of macro- and microstructure compared with those characteristic of the cast wheels.