PROPERTIES AND USES OF NICKEL STEEL. 691 
mild and medium-hard nickel steel. Nickel steel containing 
a high percentage of nickel is of special interest, on account 
of its ability to withstand rusting in a high degree. This 
material offers, indeed, great resistance to breaking strains, 
and possesses considerable elongation; but its elastic limit 
is much lower than in steel containing about 6 per cent. 
of nickel, and it is therefore less adapted for parts of 
machines subject to great strains. Its use was intended for 
fire-boxes in the construction of locomotives, and for similar 
purposes. 
The tests recorded in Tables I. to X. and XII. to XIV. 
inclusive were made on three kinds of steel in the author’s 
laboratory, and include tension, compression, shear, and 
torsion tests. They are denoted in the test sheets, as 
follows :— 
F, mild; T, medium-hard; E, non-rusting. 
The analyses of the three qualities was as follows :— 
Manga- | Phos- Sul- 
: ey. _| Nickel, 
ils ASE 8 nese. | phorus. | phur. Popes per cent. 
BOO 0-012 0°33 0°008 | 0:034 | 0°056 6°01 
T| 0°34 0:224 G:24 0°013 | 0-010 | 0°064 6°10 
E| 0°566 | 0°338 6°49 0-016 |0°019)0°064| 25°74 
Table XV. gives the results of corrosion tests. 
Table XI. gives the results of testing specimens of steel 
manufactured by Messrs. Vickers, of Sheffield, in a similar 
manner to the specimens of nickel steel. These were cut 
out of an ordinary railway axle, and were tested for the 
sake of comparing carbon steel of high quality with nickél 
steel. 
Tables XVI. to XVIII. give the results of testing nickel 
steel containing approximately 6 per cent. nickel, but of 
three degrees of hardness, which include tensile, alternating, 
bending, and impact tests, 
Tensile Tests.—The tensile tests made in the author’s 
laboratory consisted in the first place in the determination 
of the elastic limit and coefficient of elasticity, the exten- 
sions being measured by Marten’s mirror extensometer.* 
The test pieces were afterwards divided between the refer- 
*See Journ. Roy. Soc., Vol. XXXI., pp. 89-111. 
