GB583162A - Improvements relating to heat-resisting alloys - Google Patents

Abstract

An article or part subjected in use to stress at high temperature, such as a part of an internal-combustion engine or of a steam or gas turbine or other prime mover or of a furnace, is made from an alloy containing at least 20 per cent. of nickel, 1.5-5 per cent. of titanium, 0-30 per cent. of chromium, 0-60 per cent. of iron, and 0-0.25 per cent. of carbon, with or without up to 20 per cent. of tungsten or molybdenum or both, up to a total of 10 per cent. of other elements such as silicon, manganese, niobium, vanadium, and aluminium, and small amounts of phosphorus, arsenic, antimony, and tantalum; or, if the iron content does not exceed 20 per cent., up to 9 per cent. of cobalt may also be present. The article or part is heated at at least 900 DEG C. for long enough for equilibrium at that temperature to be reached, followed by cooling rapidly, and it may be reheated before it is put into service to a temperature at or above that to which it will be subjected in service. In order to reduce the initial creep in service, the article or part may first be subjected to stress resulting in permanent deformation, e.g., an elongation of 0.1 per cent. Specifications 420,580 and 504,864 are referred to.