Abstract
The author confines his treatment to two of the newer and less well-known ferrous alloys: (1) so-called “stainless” iron, a steel containing from 12 to 16 per cent of chromium and less than 0.12 per cent carbon; and a “super” stainless iron containing from 12 to 20 per cent of chromium and 7 to 10 per cent of nickel. The former not only resists corrosion but is readily machinable; it is susceptible to heat treatment, under which it attains remarkable physical properties fitting it for a wide range of engineering applications. The second alloy, the strength of which is increased by hot or cold wording rather than by heat treatment, resists corrosion much better than the first one, but is more difficult to form and machine. Further, it is from 7 to 15 per cent lighter than other corrosion-resisting metals and alloys. Both alloys have high tensile strength at elevated temperatures; the latter being the better in this respect, however, having an ultimate tensile strength of 25,500 lb. at 1650 deg. fahr.
