| 摘要 |
PROBLEM TO BE SOLVED: To provide a low thermal expansion material in which the machinability of an Fe-Ni-(Co) based material is solved, and which has excellent plating properties. SOLUTION: The free-cutting, low thermal expansion material consists of an Fe-Ni based material or an Fe-Ni-Co based material, and has free-cuttability by controlling the content of sol.Al to 0.01 to 0.1 mass%. The free-cutting, low thermal expansion material concretely has a composition containing, by mass, 25 to 55% Ni, and 0.01 to 0.1% Al, and the balance substantially Fe, and in which the content of sol.Al is controlled to 0.01 to 0.1% also so as to satisfy (Al-sol.Al)≤0.01. Alternatively, the free-cutting, low thermal expansion material has a composition containing 25 to 55% Ni,≤20% Co, and 0.01 to 0.1% Al, and the balance substantially Fe, and in which the content of sol.Al is controlled to 0.01 to 0.1% also so as to satisfy (Al-sol.Al)≤0.01. COPYRIGHT: (C)2003,JPO
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