Method for improving an iron-nickel-chromium-manganese alloy for timepiece applications
AssigneeNivarox-FAR S.A.
InventorChristian Charbon
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Abstract
A method for improving an iron-nickel-chromium-manganese alloy for timepiece applications, particularly for producing a balance spring, is described. The base alloy contains, by mass, from 9.0% to 13.0% of nickel, from 4.0% to 12.0% of chromium, from 21.0% to 25.0% of manganese, from 0 to 5.0% of molybdenum, and/or from 0 to 5.0% of copper in addition to iron. The alloy is hardened while its anti-ferromagnetic properties are maintained by introducing 0.10% to 1.20% of carbon and 0.10% to 1.20% of nitrogen interstitially, based on the mass of the base alloy.
Claims10
A method for hardening an iron-nickel-chromium-manganese base alloy, the method comprising:
- introducing, based on the base alloy, 0.10% to 1.20% by mass of carbon and 0.10% to 1.20% by mass of nitrogen interstitially into the base alloy with a mass ratio of carbon to nitrogen ranging from 1.0 to 2.0 so as to harden the base alloy and maintain anti-ferromagnetic properties of the base alloy,
- wherein the base alloy comprises, by mass:
- from 4.0% to 13.0% of nickel,
- from 4.0% to 12.0% of chromium,
- from 21.0% to 25.0% of manganese,
- from 0 to 5.0% of molybdenum and/or from 0 to 5.0% of copper, and
- iron.
Dependencies are inferred from the claim text.