Vliv metalurgie a technologie odlévání na kvalitu těžkých ocelových odlitků

Abstract

This thesis deals with an impact of physico-chemical processes taking place in reladling and casting of quality steel castings. First, the analysis of manufacture of these steels with different alloying degrees is mentioned, and the representatives of furnace units for steel making are shown. The paradigmatic case study of a steel flow at its outlet from the ASEA ladle and selected stopper ladle. The integral part of this thesis is also paradigmatic case study of a steel flow in the gating system. The original method of the pouring of castings, and newly designed method tested in practice are mentioned. In the course of particular operations with steel before and after its casting, the measurements of an oxygen activity, hydrogen content, and molten steel sampling for a subsequent chemical analysis were conducted. In the concluding part of the theses, the appraisal of micropurity and mechanical properties of selected heats is conducted.