| 摘要 |
<p>PURPOSE:To considerably improve the internal characteristic of a steel ingot without requiring any special work and equipment by transferring the molten slag in a pan after ending of ingotting work onto the molten stel by suitable means and holding the composition thereof to the specific component composition such as CaO, SiO2, CaF2. CONSTITUTION:In an electroslag holt top method (EST method), the molten slag remaining in a pan after ending of ingotting work is transferred onto the molten metal in the head flask by using suitable means, after which the slag composition is maintained at 1.5-5 in Cao/SiO2 ratio, 1-3 in (CaO+MgO)/(SiO2+Al2O3), CaF2<20% and (T, Fe+T.Mn)<2% without addition of any slagging agent or by adding a suitable amount of a slagging agent. As a result, the expected desulfurization efficiency and the improvement in the cleanliness of inclusions may be realized; at the same time, the increas in the hydrogen contents in the steel ingot is prevented. This method is effective for the production of steam turbine rotors and the like.</p> |
