Odstředivě lité válce s HSS pracovní vrstvou

Abstract

The main topic of the theoretical part of this thesis is the description of the basic principles of the production technology of centrifugal casting of cylinders. The thesis discusses the basic types of materials that are used for the working layer of centrifugally cast rolls for hot rolling. In the practical part, the influence of technological parameters in the production of centrifugally cast rolls with HSS working layer on the microstructure and hardness of the working layer was studied. It was found that the use of a very low cooling rate from the high temperature annealing temperature (1020 °C) is inappropriate as it leads to the formation of a high proportion of undesirable troostite. Furthermore, the effect of repeated tempering at temperatures of 525 °C and 530 °C on the decrease of the content of residual austenite and the hardness of the working layer was studied. Part of the practical part of the work was also the characterization of the microstructure in the area of the mixing band of the HSS working layer and the core cast iron.