NICKEL STEEL. Iron has a strong affinity for nickel, and alloys with it in all proportions very readily. The fol lowing is the average composition of nickel steel as made in the United States: Carbon . 0.24-0.2S per cent. Sulphur 0.02-0.03 " " Manganese " Phosphorus 0.01-0.03 " " Nickel 3.00-5.00 " " Physical Pro perties.—Resistance to corrosion is its principal peculiarity. Numerous tests have been made, espe cially in sea water, which is very de structive to iron or steel, the results of which have demonstrated the fact that nickel steel when used alone would out last the best of ordinary steels. This was proved by tests with propellers, tor pedo netting, metal sheathing for vessel bottoms, etc. There seems some doubt, however, as to its applicability to boil ers, where its high elastic limit would permit much lighter construction. Some experiments indicate that nickel steel cor rodes rapidly in pure water and in the presence of various boiler compounds, while on the other hand an English au thority cites an experiment indicating a corrosion of but one-half to three-quar ters that of ordinary steels.
Nickel steel is a noble metal, for while it has a remarkable resistance to applied stresses, yet it is almost as easily worked as soft steel, is not brittle while hot or cold, is not much affected by tempering or annealing as compared with carbon steel, and is remarkably homogeneous.
It is very common for tempered nickel steel to have a tensile strength of 200, 000 pounds per square inch without be ing brittle. If we compare this with the 60,000 pounds for low carbon steel, we see that there is still plenty of room at the top, for most of the steel used to day is low in carbon. Commander Eaton, U. S. N., says that the United States Government first bought nickel to use in steel in 1890, that the first nickel steel plate was tested in 1893, in July, and for a time all armor for United States ves sels was made of nickel steel. See IRON and STEEL.