Patent ID: 8562713
Filing Date: 2013-10-22
Classification: C21C,C22B,Y02P

Abstract:
1. In a single arc furnace process of making at least four types of steel, the steps of providing a single arc furnace, charging solid scrap into the single arc furnace in an amount sufficient to comprise at least a bulk of the weight of steel which is to be subsequently subjected to vacuum treatment, adding heat to the solid scrap to melt the solid scrap to thereby form a melt containing carbon, tapping at least the bulk of the melt from the single arc furnace into a tapping vessel to form a heat, transferring the tapped heat from the arc furnace in the tapping vessel to a single ladle metallurgical station, adding alloys to the tapped heat in the ladle metallurgical station in an amount sufficient to bring at least some constituents of the tapped heat up to desired constituent levels, increasing the temperature of the heat at the ladle metallurgical station sufficiently to super-heat the heat with respect to a desired teeming temperature, transferring the super-heated heat to a vacuum treatment station, subjecting the super-heated heat to a vacuum and a purging gas in an amount sufficient to stir the super-heated heat so as to expose the surface of the heat, and also portions of the heat remote from the surface, to the vacuum whereby hydrogen and oxygen in the super-heated heat are removed from the heat by exposure of the heat to the vacuum, terminating subjection of the heat to the vacuum and the purging gas at a time after degassing of the heat has occurred and the temperature of the heat has reached an acceptable teeming temperature, immediately transferring the heat treated in accordance with the foregoing steps to a teeming station, teeming a desired quantity of the treated heat into at least one primary mold at the teeming station, and solidifying the teemed heat at the teeming station.