Titaniums having excellent impact resistance and manufacturing methods
AssigneesNippon Steel Corporation, MIC Japan, Ltd.
InventorsKazuhiro Takahashi, Motomi Masaki, Kazuyuki Miura, Tatsuo Ohya
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Abstract
Titaniums having excellent impact resistance are manufactured by methods that attain good cold workability by controlling the concentrations of oxygen, nitrogen, carbon and iron contained in ordinary pure titaniums in the desired range, applying combinations of preliminary working and annealing before or during the forming process, and controlling the Vickers hardness in the cross-sectional area to the desired range according to the concentrations, without adding aluminum, molybdenum, vanadium or other alloying elements.
Claims4
Titanium having impact resistance consisting essentially of total concentration S of oxygen, nitrogen and carbon, [O], [N], and [C], between 0.04 and 0.27 mass percent, not more than 0.1 mass percent iron, substantially no copper, and the balance being titanium and unavoidable impurities, and having Vickers hardness Hv* controlled by work-hardening to the range satisfying one of the following equations (1), (2) and (3):
- when 0.04≦S≦0.09 (mass percent)
- 150≦Hv*≦400×S+175 (1)
- when 0.09≦S≦0.20 (mass percent)
- 510×S+104≦Hv*≦400×S+175 (2)
- when 0.20≦S≦0.27 (mass percent)
- 510×S+104≦Hv*≦255 (3)
- wherein S:
- [O]+[N]+[C] (mass percent)
- Hv*:
- Vickers hardness in the cross-sectional area of the work-hardened product.
Dependencies are inferred from the claim text.