Metal structure, method of manufacturing metal structure, spring component, chronograph coupling lever for timepiece, and timepiece
A metal structure includes, by mass %, Fe: 10% to 30%; S: 0.005% to 0.2%; and the balance consisting of Ni and unavoidable impurities, in which a maximum grain size of the metal structure is 500 nm or less. The metal structure preferably has one or more of a stress relaxation rate of 10% or less, a lattice constant of 3.535 Å to 3.56 Å, a yield stress of 1500 MPa or more, a Young's modulus of 150 GPa or more and a Vickers hardness of Hv 580 or more.
1. A metal structure comprising, by mass %:
Fe: 10% to 30%;
S: 0.005% to 0.2%; and
the balance consisting of Ni and unavoidable impurities,
wherein a maximum grain size of the metal structure is 500 nm or less, and
wherein a stress relaxation rate of the metal structure is 10% or less.
2. The metal structure according to claim 1 , wherein a lattice constant of the metal structure is 3.535 Å to 3.56 Å.
3. The metal structure according to claim 1 , wherein a yield stress of the metal structure is 1500 MPa or more and a Young's modulus of the metal structure is 150 GPa or more.
4. The metal structure according to claim 1 , wherein a Vickers hardness of the metal structure is Hv 580 or more.
5. A spring component which is formed by the metal structure according to claim 1 .
6. A timepiece which uses the spring component according to claim 5 as a component thereof.
7. The metal structure according to claim 2 , wherein a yield stress of the metal structure is 1500 MPa or more and a Young's modulus of the metal structure is 150 GPa or more.
8. The metal structure according to claim 2 , wherein a Vickers hardness of the metal structure is Hv 580 or more.
9. The metal structure according to claim 3 , wherein a Vickers hardness of the metal structure is Hv 580 or more.
10. The metal structure according to claim 7 , wherein a Vickers hardness of the metal structure is Hv 580 or more.
11. A spring component which is formed by the metal structure according to claim 2 .
12. A spring component which is formed by the metal structure according to claim 3 .
13. A spring component which is formed by the metal structure according to claim 4 .
14. A spring component which is formed by the metal structure according to claim 7 .
15. A spring component which is formed by the metal structure according to claim 8 .
16. A method of manufacturing a metal structure, the method comprising:
forming by an electroforming a metal structure including, by mass %,
Fe: 10% to 30%;
S: 0.005% to 0.2%; and
the balance consisting of Ni and unavoidable impurities; and
performing a heat treatment to the metal structure under conditions in which a heat treatment temperature is 140° C. to 350° C. and a Larson-Miller parameter is in a range from 7500 to 9500.
17. The method of manufacturing a metal structure according to claim 16 , wherein the heat treatment temperature is equal to or higher than 140° C. and lower than 275° C.
18. A chronograph coupling lever for a timepiece, the chronograph coupling lever comprising:
a spring component,
wherein the spring component includes a metal structure,
wherein the metal structure includes by mass %,
Fe: 10% to 30%,
S: 0.005% to 0.2%,
and the balance consisting of Ni and unavoidable impurities, and
wherein a maximum grain size of the metal structure is 500 nm or less.
19. A timepiece comprising:
a chronograph coupling lever having a spring component which uses the chronograph coupling lever for a timepiece,
wherein the spring component includes a metal structure,
wherein the metal structure includes by mass %,
Fe: 10% to 30%,
S: 0.05% to 0.2%,
and the balance consisting of Ni and unavoidable impurities, and
wherein a maximum grain size of the metal structure is 500 nm or less.