Problematika vytékání ochranných zásypů ingotových hlav v kovárenských pecích společnosti Vítkovice Heavy Machinery a.s.

Abstract

This thesis deals with the issuing of protective and insulating powders from the heads of steel ingots in forging furnaces. Protective powders are used to isolate the metal surface from the surrounding environment when casting steel into molds. After cooling and subsequent heating of ingot for further processing technology then there is a leak of this matter. The powder is used ingots exothermic and insulating powder, consisting mainly of the oxides SiO2 and Al2O3. For small ingots for the exothermic mixture of powder and protective filling, in large ingots are used only protective powder, in practice better known under the working title „rice husks“. In addition to these two powders is present in the head and ingot casting the powder, which is to protect the metal surface in the actual casting and also to facilitate stripping of ingot. The upper forging temperature, however, ranges from 1 150 - 1 250 ° C, which would not melt mixture backfilling, backfilling as producers declare liquidus temperature of the backfill mixture at high temperature deformation. The leakage ingot´s heads, however, constantly occur, for large and small ingots, regardless of heating time, or quality of steel.