Nickel Steel Boiler Plates.
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 151⁄2 per cent. in each specimen, and the reduction of area at fracture was 291⁄2 per cent. and 261⁄2 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.