鋼塊の凝固過程に関する研究(II)

凝固過程における大型鋼塊の固相附近における熔鋼の化学的変化

抄録

The authors made investigations into the state of molten steel near the solid phase of a ingot of 9-20 tons with a sampler which had been described in report No. 1. (p. 467-470, April, 1958 of this issue.)
The results obtained were as follows:
1. Carbon, silicon, manganese, phosphorus, sulphur, hydrogen and nitrogen concentrated into liquid phase along with the progress of solidification.
The quantity of it, (in case it was indicated based on the value at a tundish immediately before casting), was as follows: 1.40 times for carbon, 1.10 times for silicon and manganese, 1.50 times for phosphorus and sulphur above 2.00 times for hydrogen and nitrogen
2. In the process of solidification, the total quantity of oxygen in molten steel near the solid-liquid border line showed inclination to decrease with the progress of the solidification.
However, it increased a little when the progress of solidification reached as far as near the sinkhead.
Both Al₂O₃ and MnO were observed to have almost the same tendency as total oxygen and SiO₂ was noticed to have an inclination of a little more concentrating into the liquid phase with the progress of solidification. Content of FeO was almost negligible, being shown no clear variations and generally, the variations of oxygen and oxides were not outstanding.
In general, there existed some relations between the concentration of these elements in the liquid phase during solidification and defects in ingots.