US1504338A - Alloy comprising iron, nickel, chromium, tungsten, or molybdenum - Google Patents

Description

i I I i l I PIERRE GIRIN, OFJPARIS, FRANCE, ASSIGNORTO SOCIETE ANONYME DIE COLENTRY, FOUBCHBAULT dc JDJECAZJEVILLE, F PARIfi lFNfiE.

ALLOY COMPRISING IRON, NI, CHROMIUM, TIJ' NGSTEN, OR MOLYBDENUM.

No Drawing.

To'all whom it may concern:

Be it known that I, PIERRE Gmm, a citizen of the Republic of France, residing in Paris, France, have invented certain new n and useful Improvements in a New Alloy Comprising Iron, Nickel, Chromium, Tungsten, or Molybdenum, of which the following is a specification.

The attainment of an industrial alloy hav- 1o ing a high mechanical resistance at hi h temperatures and capable of indefinit y preserving its properties, in spite of a prolonged exposure ,to these temperatures, is

- a problem which has not yet received a practical solution. In fact, the most resistant reheating annuls the action of the treatment.

The hi h speed steels certainly preserve their ardnes's at a temerature higher than the other steels, and after they have been tempered possess a high resistance even up to a red heat, but besides the drawbacks which result from their fragility and dimculties of a practical'nature due to the extremely high temperature of their-treatment, they do not present the desired stability W when the temperature exceeds 600; in fact,

not only an accidental excess of temperature beyond the regulated value, but even prolonged exposure to this temperature produce a gradual disappearance of the initial hardness and a progressive diminution of resistance. Finally, they are very oxidizable.

In addition, the invention of gas motors, gas turbines and other thermal machines intended to act above the temperature of red heat, and the discovery of chemical synthetic processes using at the same time high tem peratures and high pressures, render the realization of a metal possessing certain qualities at high temperature extremely desirable.

The present invention concerns an alloy of iron, nickel, chromium and tungsten, and including, perhaps, molybdenum or vanadium, cobalt and titanium. This alloy is easy to obtain in large quantities, and capable of being moulded, forged, rolled, wire drawn, or otherwise Worked, without dimculty, possessing at the temperature of 800 a resistance almost equivalent to that of cold iron, non-fragile, practically inoxidizable at Application filed December 9, 1918. Serial No. 2%,985.

high temperatures, even in a very oxidizing temperature, and at the same time possessing properties which are strictly reversible; by this term we understandthat the properties at a given temperature depend solely on that temperature and in no Way on the preceding temperatures that have been'obtained,

nor on an exposure. more or-less long to the temperature used. The alloy may contain,

for example:

- Per cent.

Nickel to Chromium 10 to 15 Tungsten 2 to 5 Manganese 1 to 2 Carbon 0.3 to 0.6

Iron forming the remainder.

defined 0.5 to 1 per cent of vanadium, or

0.1 to 0.2 per cent of titanium.

The alloy thus obtained forms a solid homogeneous solution; no thermal treatment can, consequently, modify its properties. The combined action of chromium and of tungsten (this last metalbeing capable of being replaced wholly or partially by molybdenum) and, if it is present, of vanadium, is to confer on the alloy of iron and nickel a very high resistance when heated; we can obtain easily 25 to 35 kgs. per sq. mm. with an elastic limit of 20 to 30 kgs. and a coefiicient of elongation of 40 per cent at. a temperature of 800, while still preserving a total absence of fragility. These additional elements also render the alloy extremely resistant to the attack of acid vapours, as well as of hot oxidizing and moist gases This chemical unalterability is of the greatest. importance for all applications, since it not only ensures the metal against corrosion, but also ensures the preservation of the initial mechanical properties, in contradistinction to thatwhich takes place with carbon steels which, when heated for a long time in an atmosphere rich in hydrogen, finally become decarburized and lose their solidity.

This alloy is certainly very suitable for the manufacture of gas turbines, or for receptacles employed in chemical industry, for reactions which take place at high temperature and at high pressures, and which pro duce corrosive gases or other substances.

Having thus described the nature of the said invention and the best means I know of carrying the same into practical effect, I claim A highnickel ferrous alloy containing 10 nickel, 60 to 70 per cent, chromium, 10 to 15 per cent, tungsten, 2 to 5 per cent, manganese l to 2 per cent and carbon, 0.3 to 0.6 per cent, such alloy having at elevated temperatures great mechanical resistance and also great resistance to chemical agents and susceptible of retaining indefinitely its initial properties, notwithstanding prolonged service. v

In witness whereof, I have hereunto signed my name.

PIERRE GIRIN.