0.06 0.014 0.032 0.009 0.08
Note the practical elimination of phosphorus.
3:40 P.M.--The oxidizing (black) slag is now poured and skimmed off as
clean as possible to prevent rephosphorizing and to permit of adding
carburizing materials. For this purpose carbon is added in the form
of powdered coke, ground electrodes or other forms of pure carbon.

The deoxidizing slag is now formed by additions of lime, coke and
fluorspar (and for some analyses ferrosilicon). The slag changes
from black to white as the metallic oxides are reduced by these
deoxidizing additions and the reduced metals return to the bath.
A good finishing slag is creamy white, porous and viscous. After
the slag becomes white, some time is necessary for the absorption
of the sulphur in the bath by the slag.

The white slag disintegrates to a powder when exposed to the atmosphere
and has a pronounced odor of acetylene when wet.

Further additions of recarburizing material are added as needed to
meet the analysis. The further reactions are shown by the following:

3:40 P.M.--Recarburizing material added:
130 lb. ground electrodes.
25 lb. ferromanganese.
Analysis:
Carbon Silicon Sulphur Phosphorus Manganese
0.76 0.011 0.030 0.008 0.26

To form white slag there was added:

225 lb. lime.
75 lb. powdered coke.
55 lb. fluorspar.
4:50 P.M.--
Analysis:
Carbon Silicon Sulphur Phosphorus Manganese
0.75 0.014 0.012 0.008 0.28
Note reduction of the sulphur content.

During the white-slag period the following alloying additions were
made:

500 lb. pig iron.
80 lb. ferrosilicon.
9 lb. ferromanganese.
146 lb. 6 per cent carbon ferrochrome.

The furnace was rotated forward to an inclined position and the
charge poured into the ladle, from which in turn it was poured
into molds.

5:40 P.M.--Heat poured.
Analysis:
Carbon Silicon Sulphur Phosphorus Manganese Chromium
0.97 0.25 0.014 0.013 0.33 0.70

Ingot weight poured 94.0 per cent
Scull 2.7 per cent
Loss 3.3 per cent

Total current consumption for the heat, 4,700 kW.-hr. or 710 kw.-hr.
per ton.

Electric steel, in fact, all fine steel, should be cast in big-end-up
molds with refractory hot tops to prevent any possibility of pipage
in the body of the ingot. I