It has been found that the addition of about three per cent. (3.16 to
3.32) of nickel to ordinary soft steel produces most favorable results;
thus it has been shown by Riley that a particular variety of nickel
steel presents to the engineer _the means of nearly doubling boiler
pressures without increasing weight or dimensions_.
In a recent experiment made with Bessemer steel rolled into
three-fourths inch plates from which a number of test specimens were
cut, the elastic limit was respectively 59,000 pounds and 60,000
pounds. The ultimate tensile strength was 100,000 pounds and 102,000
pounds, respectively. The elongation was 15-1/2 per cent. in each
specimen, and the reduction of area at fracture was 29-1/2 per cent.
and 26-1/2 per cent. respectively. These figures show that the elastic
limit and ultimate tensile strength was raised by the nickel alloy to
almost double the limits reached in the best grades of boiler plate
steel, and the elongation was reduced to a scarcely appreciable extent.
The experiment had for its object, the reproduction, as nearly as
possible, of the alloy used in the nickel steel armor plate made at Le
Creusot, France, and the result was reported to the Secretary of the
Navy at Washington. The new plate showed a percentage of 3.16 nickel,
as against 3.32 for the imported plate.