690 PROCEEDINGS OF SECTION H. 
Nickel Steel from the Bethlehem Iron Works.—In the 
Bethlehem Iron Works, U.S.A., nickel steei forgings are 
made from fluid compressed, acid open-hearth steel, and are 
carefully annealed after forging. To get the best results it 
is necessary to use an ingot twice the diameter of the finished 
forging to be made from it, in order that the proper amount 
of work shall enter into the metal during the time of its 
reduction in size under_the press. The ingot also should 
have from 30 to 50 per cent. extra metal at the top which 
is cut off, as only the lower portion of the ingot is solid and 
suitable for forging purposes. Whenever the form and size 
of the forgings will allow of such treatment, they should be 
made hollow by boring, and they may also be oil tempered. 
Presses should always be used in preference to hammers, 
and should produce a pressure penetrating ‘to the centre 
and causing a flow throughout the mass. 
The steel used in the field magnet rings of the large 
Niagara electric generators was made at the Bethlehem 
works. Each ring was forged in one piece, without welding, 
from an ingot of nickel steel, 54 inches in diameter and 197 
inches long. The ingot was cast solid and compressed by 
hydraulic pressure in the fluid state and during solidifi- 
cation. A hole was bored in the ingot, which was subse- 
quently expanded on a mandrel under a 14,000-ton hydraulic 
forging press. The material was tested after forging to 
obtain the physical qualities desired, the results being as 
follow :— 
| 
Sample'No Tensile Strength) Elastic Limit, | Elongation on two 
* |pounds per sq. in.) pounds per sq. in. | inches, per cent. 
1 82,915 | 53,560 27°05 
2 81,110 47,230 25°75 
3 82,140 49,280 22°50 
Average 82,055 50,023 25°10 
Tests of Nickel Steel manufactured by the Firm of Fried. 
Krupp, of Essen, Germany.—The firm of Fried. Krupp, of 
Essen, manufacture substantially two kinds of nickel steel, 
differing as regards the quantity of nickel contained there- 
in; that is to say, one has a comparatively small quantity 
of nickel amounting to from 3 to 8 per cent., according to 
requirements, and the other contains a large quantity of 
nickel amounting to 25 per cent. and more. The former is 
made of various degress of hardness, as ingot nickel iron, 
