The diploma work is addressing the problem of bonding between layers in multi-layered cast rolls with a working layer made of hypereutectoid high sped steel from the standpoint of thermo-mechanical fatigue during rolling. Multilayer cast rolls are made of three layers: the outer working layer, intermediate layer, and core, between which a metallurgical bond is created through solidification. Segments of all three layers (in cross-section) were turned from a multi-layered cast roll for testing on the thermo-mechanical simulator Gleeble 1500. Samples were prepared at places with an ultrasonically acceptable bond as well as at places with limited microstructural errors. Cyclic loading was applied on the samples until they fractured. The fractured surfaces of the tested samples were viewed and evaluated under optical and electron microscope. The results were then compared between the good and the bad bond between layers. The results can serve for better understanding of solidification in the case of good and bad bond formation in cast rolls.
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