GB352964A - Process for improving iron-titanium alloys - Google Patents

Abstract

Iron-titanium alloys are hardened by quenching or cooling in air from a temperature between 700 DEG C. and 1350 DEG C. and then artificially ageing by annealing at a temperature between 320 DEG C. and 600 DEG C. The process may be applied to binary iron-titanium alloys with or without carbon, the titanium content being for example between 3 and 6 per cent; to alloys of iron, from 0,5 to 8 per cent titanium and up to either 40 per cent nickel or 8 per cent manganese with or without carbon; or to these alloys with additions of up to 25 per cent chromium, 15 per cent cobalt, 5 per cent molybdenum, 3 per cent vanadium, 4 per cent silicon, 25 per cent tungsten, or any combination of these elements, the minimum iron content being about 50 per cent. To obtain maximum hardness the nickel content is preferably greater than the titanium content. Alloys referred to contain 5,54 per cent titanium, 7,4 per cent nickel and the balance iron; 5,4 per cent titanium, 7,6 per cent nickel, 12,3 or 20,4 per cent chromium and the balance iron; and it is stated that the process may be applied to the stainless steels containing 20 per cent chromium and 7 per cent nickel after addition of titanium and to the titanium steels containing about 36 per cent nickel and 4,5 per cent titanium. The alloys may be cooled after the first heating by spraying with compressed air. The Specification as open to inspection under Sect. 91 (3) (a) states that similar effects were produced "with additions of zircon." This subject-matter does not appear in the Specification as accepted.