GB626204A - Improvements relating to alloys for use at high temperatures - Google Patents

Abstract

A nickel-base, iron-containing alloy, suitable for the manufacture of articles and parts used at high temperature under stress, contains 10-25 per cent of chromium and 1.5-5.0 per cent of titanium with or without any one or more of the elements aluminium, niobium and tantalum, and the remainder nickel. The iron content of the alloy is so low that no significant amount of embrittling phase is produced even if the alloy is heated to 1000 DEG C., cooled to room temperature at a rate sufficiently fast to retain the solution created during heating, reheated to 600 DEG C.-800 DEG C. and subjected to prolonged heating at 650 DEG C.-900 DEG C. The maximum permissible amount of iron is related to the chromium content by a graph accompanying the Specification. The total content of titanium and the aluminium, niobium and tantalum contents, measured in terms of titanium, must be at least 3 per cent and does not exceed 10 per cent. For this purpose 1 per cent of niobium is regarded as equivalent to 0.5 per cent titanium, 1 per cent of aluminium is equivalent to 1.25 per cent titanium and 1 per cent tantalum is equivalent to 0.25 per cent titanium. The nickel may be partly replaced by cobalt, so that the alloy contains up to 45 per cent cobalt. Up to 2 per cent each of copper, manganese, tungsten, and/or vanadium, up to 5 per cent of molybdenum, up to 1 per cent of nitrogen, up to 2 per cent of silicon may also be present in the alloy. Specifications 572,779, 572,861 and 583,845 are referred to. Reference has been directed by the Comptroller to Specifications 572,779 and 572,861.