Optimalizace vlastností děrovacích trnů z vysoce legované chromové oceli

Abstract

The aim of this diploma thesis was to find out how different process conditions, such as the solidification time of the castings in the molds and the subsequent heat treatment at different temperatures, affect the properties of the material, which will affect its final service live. Subsequently, wear-resistant cast irons, their classification and applications are described in a separate chapter. The problems of solidification of castings and which factors influence the crystallization of cast irons in different types of systems are also discussed. The heat treatment of wear-resistant cast irons and the influence of alloying elements on the properties of wear-resistant cast irons are also discussed in the theoretical part. The final part of the theoretical analysis is focused on carbides in wear-resistant cast irons. In the experimental part, the microstructural analysis of automatic mandrels was carried out. The documentation of the microstructure using light and scanning electron microscope, hardness measurements, determination of the proportion of residual austenite by X-ray diffraction analysis and fractographic analysis of the cracked specimen were performed.